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See detailChange in naming abilities between the ages of 50 and 90: The importance of analyzing naming latency
Verhaegen, Clémence ULg; Poncelet, Martine ULg

Poster (2012, September)

Introduction This study tests the controversial hypothesis that word naming difficulties may arise in individuals as young as their 50s. According to Feyereisen (1997), these difficulties begin at the age ... [more ▼]

Introduction This study tests the controversial hypothesis that word naming difficulties may arise in individuals as young as their 50s. According to Feyereisen (1997), these difficulties begin at the age of 70, but Nicholas, Connor, Obler, and Albert (1998); Connor, Spiro, Obler, and Albert (2004) observed subtle signs of decreased naming performance in participants in their 50s. However, these studies focused on naming accuracy. To our knowledge, no study has analyzed naming latencies in participants in their 50s in comparison with younger participants. We assume that such analyses may highlight more subtle difficulties in naming. In our study, both naming latencies and naming accuracy were analyzed in a picture naming task presented to 4 age groups: 25-35, 50-59, 60-69 and above 70 years old. If people in their 50s experience subtle naming difficulties, these should be reflected in longer picture naming latencies compared to younger participants. In participants above 70 years of age, the decline should be more apparent and may be underlined not only by slower naming latencies but also by lower picture naming scores. The explanation for naming difficulties in aging is also a matter of debate. According to some authors (e.g., Salthouse, 1996), these difficulties are a consequence of a general slowing in all cognitive tasks, including language, in the elderly. However, other theories suggest that the relevant difficulties are more language-specific and are due to connection weaknesses across the entire language system, leading to more naming errors and longer naming latencies (e.g., Burke, MacKay, Worthley, & Wade, 1991). In order to determine the extent to which the slowing of naming latencies in the elderly is related to a slowing of cognitive processing, participants’ cognitive processing speed was assessed with an odd/even judgment task. We were also interested in seeing whether slowing on the odd/even judgment task arises at the same age than slowing on the picture naming task. Methods Participants Four groups of 30 participants took part in the present study: (1) between 25 and 35 years of age, (2) between 50 and 59 years of age, (3) between 60 and 69 years of age and (4) above 70 years of age (70+). All subjects were native French speakers and reported no history of neurological, cardiac, neuropsychological or psychiatric disorders, and no uncorrected hearing or visual problems. Dementia was excluded with the Mattis Dementia Rating Scale (Schmidt, Freidl, Fasekas, Reinhart, & Grieshofer, 1994). No differences between groups were found for vocabulary level (Mill Hill test; Deltour, 1993) or socio-economic background. Materials Participants performed a picture naming task (150 black and white drawings selected from the set of Bonin, Peereman, Maladier, Méot, and Chalard, 2003). Both the number of correct responses and naming latencies were analyzed. We also analyzed response latencies on an odd/even judgment task on 50 digits from 1 to 9, to assess cognitive processing speed. Results For the picture naming task, an analysis of variance (ANOVA) performed on the number of correctly named items revealed an effect of age, F(3,116)=35.36, p<.001. Tukey post hoc comparisons (p<.05) indicated that the 70+ age group named fewer items correctly than the 60-69 age group, which performed worse than the 25-35 and 50-59 age groups, which in turn did not differ from each other. However, the ANOVA performed on correct naming latencies did not show the same pattern of results. This analysis revealed an effect of age, F(3,116)=35.36, p<.001. Tukey post hoc comparisons (p<.05) indicated that the 25-35 age group responded faster than the 50-59 and 60-69 age groups, which did not differ from each other. The 70+ age group responded more slowly than the 3 younger groups. For the odd/even judgment task, the ANOVA performed on response latencies indicated an effect of age, F(3,116)= 96.40, p<.001. Tukey post hoc comparisons (p<.05) showed that the 25-35 and 50-59 age groups did not differ from each other and responded faster than the 60-69 and 70+ age groups, which in turn did not differ from each other. An analysis of covariance was also performed on naming latencies, using the latencies on the odd/even judgment task as covariate. There was a significant effect of age, F(4,115)=54.56, p<.001. Tukey post hoc analysis indicated that the 25-35 age group responded faster than the 50-59 and 60-69 age groups, which did not differ from each other. The 70+ age group performed more slowly than the 3 younger groups. Thus, a slowing of picture naming latencies was found in participants above 50 years of age. This slowing remained significant even when cognitive processing speed was controlled for. Discussion The increase in correct naming latencies on the picture naming task in participants in their 50s suggests the presence of subtle age-related word finding difficulties. In participants in their 60s, naming difficulties were highlighted by both a decrease in correct responses and an increase in naming latencies. Finally, in participants above 70 years of age, these difficulties became more pronounced in both naming accuracy and naming latencies. Slowing on the picture naming task appears to be greater and to arise earlier in the adult lifespan (in participants in their 50s) than slowing on the odd-even judgment task assessing processing speed (in participants in their 60s). Moreover, this slowing of picture naming latencies in participants in their 50s remained significant even when processing speed was controlled for with an analysis of covariance. In conclusion, these results support the importance of naming latency analyses in uncovering subtle naming difficulties. Furthermore, although we do not exclude a possible impact of general slowing on naming latencies in participants above 50 years of age, these findings suggest that the slowing in naming at this age observed here may be explained by a specific age-related slowing within the language system. References Bonin, P., Peereman, R., Maladier, N., Méot, A., & Chalard, M. (2003). A new set of 299 pictures for psycholinguistic studies: French norms for name agreement, image agreement, conceptual familiarity, visual complexity, image variability, age of acquisition, and naming latencies. Behavior Research Methods, Instruments, & Computers, 35(1), 158-167. Burke, D. M., MacKay, D. G., Worthley, J. S., & Wade, E. (1991). On the tip of the tongue: what causes word finding failures in young and older adults? Journal of Memory and Language, 30(1), 542-579. Connor, L.T., Spiro, A., Obler, L. K., & Albert, M. L. (2004). Change in object naming ability during adulthood. The Journals of Gerontology: Series B, 59(5), 203-209. Deltour, J. J. (1993). Echelle de vocabulaire Mill Hill de J.C. Raven. Braine-le-Chateau, Belgium: Editions l’Application des Techniques Modernes. Feyereisen, P. (1997). A meta-analytic procedure shows an age-related decline in picture naming: Comments on Goulet, Ska et Kahn (1994). Journal of Speech, Language, and Hearing Research, 40(1), 1328-1333. Nicholas, M., Connor, L.T., Obler, L. K., & Albert, M. L. (1998). Aging, Language, and Language Disorders. In M. Taylor Sarno (Ed.), Acquired Aphasia (pp. 413-449). San Diego, CA: Academic Press. Salthouse, T. A. (1996). The processing-speed theory of adult age differences in cognition. Psychological Review, 103(3), 403-428. Schmidt, R., Freidl, W., Fasekas, F., Reinhart, B., & Grieshofer, P. (1994). Mattis Dementia Rating Scale. [less ▲]

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See detailThe change in the nature of the European armed forces’ education
Paile, Sylvain ULg

Learning material (2009)

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See detailChange in the protofilamentnumber and β5-tubulin appearance in supporting cells during development of the hearing organ.
Renauld, Justine ULg; Thelen, Nicolas ULg; Johnen, Nicolas ULg et al

Poster (2015, January)

The supporting cells of the hearing organ are characterized by the presence of an abundant cytoskeleton which is mainly composed of microtubules. These supporting cells have also been shown to contain a ... [more ▼]

The supporting cells of the hearing organ are characterized by the presence of an abundant cytoskeleton which is mainly composed of microtubules. These supporting cells have also been shown to contain a minor mammalian tubulin, the β5-tubulin, recently reported as a biomarker of cell proliferation. It was shown that a β-tubulin isoform can specify the microtubule architecture, as seen with the expression of the Moth β2 tubulin in the Drosophila testes which imposes the 16-protofilament (16pf) structure on the corresponding subset of Drosophila microtubules. Moreover, supporting cell microtubules are formed by 15pf instead of the canonical 13, a unique fact among vertebrates. Such a protofilament configuration has been observed in C. elegans’ neurons which are responsible for the mechanosensory sense of touch. It was also shown that these 15pf microtubules were essential to the proper functioning of these neurons. To determine the role of this particular tubulin in the auditory organ and its possible involvement in the formation of the unusual 15pf microtubules of supporting cells, we studied the spatiotemporal localization of β5-tubulin during development in rats from embryonic day 18 until P25 (25th postnatal day). Then we examined the fine structure of microtubules at the transmission electron microscope level (TEM). Our results showed that β5-tubulin, contrary to other β-tubulins, had a unique distribution in the cochlea. This β-tubulin appeared at a postnatal stage, before the opening of the Corti’s tunnel and is restricted to supporting cells, especially in pillar and Deiters’ cells. Our TEM study further indicated that these cells were composed by 13pf microtubules at P2, but by 15pf microtubules at P25. In conclusion, the architecture and composition of microtubules present in the supporting cells change during development of the Corti organ. Further experiments are now required to determine if these changes are related to the appearance of β5-tubulin. [less ▲]

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See detailChange in viability of Acetobacter senegalensis cells during gluconic acid fermentation at high temperature
Zarmehrkhorshid, Raziyeh ULg; Shafiei, Rasoul ULg; Thonart, Philippe ULg

Poster (2013, June)

Introduction: Gluconic acid (GA) is a multifunctional carbonic acid with versatile applications in food, beverage and pharmaceutical industries. Although the production of GA and its derivative dating ... [more ▼]

Introduction: Gluconic acid (GA) is a multifunctional carbonic acid with versatile applications in food, beverage and pharmaceutical industries. Although the production of GA and its derivative dating backs decades, but use of this acid and its derivatives due to high prices is currently restricted. Using a thermotolerant bacterium in production of this acid at high temperature can provide a new option for industrially cost effective production. However, fermentation productivity may be negatively affected by factors (such as high temperature) leading to loss of cell viability. Objectives: In this study, the ability of a thermotolerant bacterium, Acetobacter senegalensis, in gluconic acid production at high temperature and its survival responses to some factors including temperature and carbon sources were evaluated. Materials and Method: Different batch fermentation processes were carried out at 38 °C, and then cell viability (total dehydrogenase activity) and culturability were assessed using flow cytometry and plate counting techniques, respectively. Results: A. senegalensis oxidized 95 g/L of glucose to gluconic acid at 38 °C. In exponential growth phase, cells were less subjected to damages; but upon transition of cells to stationary phase, cell viability and culturability reduced. Consequently, due to the lack of dehydrogenase activity the specific rate of glucose consumption and gluconic acid production decreased dramatically. High temperature (38 °C), oxidation of high amount of glucose and accumulation of inhibitory compounds (possibly gluconic acid) were dominant inducers leading cells into a viable but non-culturable state (VBNC) during the course of stationary phase. In contrast, presence of ethanol accompanied with glucose, and low incubation temperature assisted in resuscitation of senescent cells of stationary phase. Conclusions: A. senegalensis is able to produce gluconic acid at 38 °C. But, due to entrance of cells into VBNC state during stationary phase, the performance of batch fermentation is adversely affected. [less ▲]

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See detailChange Management. Towards Polyphony.
Pichault, François ULg

Book published by De Boeck (2013)

This book develops a critical view on the main current theories in change management. Most of them offer partial explanations: the planning model considers change as a linear process, in which design ... [more ▼]

This book develops a critical view on the main current theories in change management. Most of them offer partial explanations: the planning model considers change as a linear process, in which design necessarily precedes implementation; the contingent model is essentially focused on contextual pressures; the political model is mainly concerned with power games, often leading to the dilution of change, etc. The book proposes an original combination of these models by referring to the actor-network theory, a french sociological perspective. Thanks to numerous case studies, it provides the reader with a rich and concrete understanding of the main phenomena linked to any change process. It leads to a multidimensional grid for assessing change processes and pleads for the adoption of a “polyphonic” management style, in which the interests of the various stakeholders concerned directly contribute to the design of the project. [less ▲]

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See detailChange Management: concepts, basics, and current trends
Lisein, Olivier ULg

Scientific conference (2009, July)

The “Change Management” question appears to be a key and crucial challenge, not only for projects managers and consultants working on the implementation of innovation projects but also for scholars having ... [more ▼]

The “Change Management” question appears to be a key and crucial challenge, not only for projects managers and consultants working on the implementation of innovation projects but also for scholars having to teach this subject to their students. What is actually hidden behind the “Change Management” concept? What are the different conceptions of the “Change Management” idea? What are the models currently highlighted in the academic and professional literature regarding the best ways to approach the “Change Management” issues and challenges? What are the main advantages and disadvantages of these models? On this basis, should some approaches and models be favored to make sure the “Change Management” initiatives and actions are a success? These questions will be presented and debated during this introductory session, aiming at giving a general overview of the “Change Management” concept, basics, and current trends. [less ▲]

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See detailChange of Tone could help Google in European Antitrust Case
Petit, Nicolas ULg

Article for general public (2012)

For the past two years, Google has worked hard to avoid facing formal antitrust charges in Europe that could mean years of expensive litigation and encourage the authorities in other parts of the world to ... [more ▼]

For the past two years, Google has worked hard to avoid facing formal antitrust charges in Europe that could mean years of expensive litigation and encourage the authorities in other parts of the world to take comparable actions. Time is running out. The European Commission could bring charges against the U.S. company for abusing its dominance in the search and advertising market in the next few weeks. [less ▲]

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See detailChangement climatique 2012
Ozer, Pierre ULg

Scientific conference (2012, December 03)

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See detailChangement climatique et familles politiques en Europe. Entre soutien et résistance aux politiques climatiques
Moelher, Karin; Piet, Grégory ULg; Zaccai, Edwin

in Courrier Hebdomadaire du CRISP (2015), 2257

Le changement climatique constitue une thématique politique relativement récente dans les agendas politiques et électoraux. Souvent, dans le grand public, la question climatique est perçue à travers la ... [more ▼]

Le changement climatique constitue une thématique politique relativement récente dans les agendas politiques et électoraux. Souvent, dans le grand public, la question climatique est perçue à travers la médiatisation des grands sommets des Nations Unies consacrés à cette problématique (Rio de Janeiro en 1992, Kyoto en 1997, Copenhague en 2009, Paris en 2015, etc.). Mais les positions que défendent les différents pays lors de ces réunions ont bien entendu été préalablement construites, entre autres, sur les scènes nationales. Les partis politiques sont à la fois les reflets des opinions publiques et les initiateurs des régulières redéfinitions des orientations politiques qui entourent la thématique du changement climatique. Ils filtrent également les demandes politiques de la société civile qui paraissent compatibles avec leur programme et leur faisabilité, et les transforment. Aux États-Unis, la polarisation politique autour de la question du changement climatique est aisément détectable . Le Republican Party se montre fortement critique, non seulement à l’égard des politiques climatiques discutées dans les cénacles de l’ONU, mais aussi, pour une part de ce courant, quant à l’existence du phénomène du changement climatique d’origine humaine. Ce type de position est particulièrement présent au sein du Tea Party. À l’inverse, le Democratic Party se montre nettement plus favorable à des objectifs climatiques, de même que, à l’instar du président Barack Obama ou du vice-président Al Gore précédemment, il reconnaît sans ambiguïté la réalité de ce phénomène physique, l’estime inquiétant et devant motiver l’action. Qu’en est-il en Europe ? L’opinion publique s’y déclare majoritairement convaincue de la réalité de changements climatiques d’origine anthropique et la trouve préoccupante, même s’il existe une part significative de la population qui en doute. Ce scepticisme se traduit-il toutefois dans les programmes électoraux de certains partis politiques, à l’instar de ce que l’on constate aux États-Unis ? Telle a été la question à la base du présent Courrier hebdomadaire. Annonçons cependant d’emblée que ce que nous désignerons ici par « climato-scepticisme », au sens strict de mise en doute du changement climatique d’origine humaine, n’est qu’un aspect assez partiel de cette étude. Nos résultats révèlent en effet que cette position climato-sceptique est extrêmement minoritaire parmi les formations politiques d’Europe. [less ▲]

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See detailChangement climatique et gestion du risque d'inondation
Dewals, Benjamin ULg

in Interview on the Belgian radio program RTBF (2009)

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See detailLe changement climatique et la gestion des risques et catastrophes
Ozer, Pierre ULg

Learning material (2014)

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See detailLe changement climatique et ses impacts sur les forêts wallonnes. Recommandations aux décideurs et aux propriétaires et gestionnaires
Laurent, Christian; Perrin, Dominique; Bemelmans, Daniel et al

Report (2009)

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See detailChangement climatique, géomorphologie littorale, désertification
Ozer, Pierre ULg

Learning material (2012)

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See detailCHANGEMENT CLIMATIQUE: CAUSES ET CONSEQUENCES (2015) - ANALYSE HOLISTIQUE -
Ozer, Pierre ULg

Scientific conference (2015, November 06)

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See detailChangement climatique: Etat des lieux 2012
Ozer, Pierre ULg

Scientific conference (2012, January 30)

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See detailCHANGEMENT CLIMATIQUE: Manger - Bouger
Ozer, Pierre ULg

Conference given outside the academic context (2015)

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See detailLe changement de dynastie et la genèse de l'alliance franco-pontificale dans les petites annales carolingiennes
Close, Florence ULg

Scientific conference (2011, February 28)

L’avancée des recherches en historiographie carolingienne a conduit ces dernières années à la remise en cause des circonstances de l'avènement du maire du palais Pépin III à la tête du royaume franc. Non ... [more ▼]

L’avancée des recherches en historiographie carolingienne a conduit ces dernières années à la remise en cause des circonstances de l'avènement du maire du palais Pépin III à la tête du royaume franc. Non seulement la sincérité des sources carolingiennes mais certains détails de la cérémonie admis de longues dates ont été mis en doute. De récentes interprétations suggèrent que les circonstances du changement de dynastie de 751 furent bien différentes de celles qui sont traditionnellement enseignées. Cette communication proposait un passage en revue de l’ensemble des témoignages de l’usurpation du trône mérovingien par Pépin III rédigés du vivant de Charlemagne. Avant d'envisager les différentes versions des événements séparant la mort de Charles Martel de l’onction de 754 véhiculées par les « petites annales carolingiennes », l'auteur revient sur les quatre textes traditionnellement invoqués pour traiter cette question : la continuation de Frédégaire, les Annales regni Francorum (annales royales), le liber pontificalis, et la clausula de unctione Pippini. [less ▲]

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See detailChangement de forme ontogénétique des structures céphaliques chez les Pomacentridae : une approche par la morphométrie géométrique
Frederich, Bruno ULg; Parmentier, Eric ULg; Vandewalle, Pierre ULg

Poster (2006, March)

Les Pomacentridae (Damselfishes), comme la plupart des poissons des récifs coralliens, possèdent un cycle de vie complexe comprenant une phase larvaire pélagique dispersive, et une phase juvénile et ... [more ▼]

Les Pomacentridae (Damselfishes), comme la plupart des poissons des récifs coralliens, possèdent un cycle de vie complexe comprenant une phase larvaire pélagique dispersive, et une phase juvénile et adulte benthique associée au milieu corallien. Le passage du stade larvaire au stade juvénile se fait au cours d’un véritable processus de métamorphose qui généralement coïncide avec la colonisation du récif. Cette transition est une phase cruciale impliquant un changement du mode de vie qui peut s’accompagner de modifications morphologiques. A l’heure actuelle, peu d’information existe sur ce qui caractérise la métamorphose des poissons récifaux d’un point de vue squelettique et leurs implications fonctionnelles. Celle-ci n’est principalement décrite que par des changements de pigmentation et des changements morphologiques telles que des modifications de proportions du corps. L’objectif de cette étude est de caractériser les changements de forme des structures céphaliques directement impliquées dans la prise de nourriture chez deux espèces de Pomacentridae : Pomacentrus pavo (Bloch, 1787) et Dascyllus aruanus (Linnaeus, 1758). Dans cette étude, la morphométrie géométrique basée sur la méthode des points repères est utilisée pour décrire les trajectoires de croissance et les changements de forme caractérisant les pièces squelettiques durant la période de colonisation du récif. Cette analyse est appliquée aux quatre unités fonctionnelles suivantes : le neurocrâne, l’ensemble « suspensorium et opercule », la mandibule et le prémaxillaire. Celles-ci sont étudiées en vue latérale. Les patrons de transformations de chaque structure durant le développement sont décrits morphologiquement au moyen de grilles de déformation. Les modifications morphologiques observées chez P. pavo et D. aruanus durant le développement vont dans le sens d’une amélioration du système de prise de nourriture par aspiration. Les principaux changements sont : un agrandissement en hauteur et en largeur du suspensorium et de l’opercule, une élévation de la crête supraoccipitale, un déplacement vers l’avant de l’articulation mandibulaire, un raccourcissement de la mandibule et un allongement du processus ascendant du prémaxillaire. Ces transformations au niveau de la tête pourraient refléter un changement de mode de prise de nourriture au cours de l’ontogénie. La comparaison des unités fonctionnelles entre les deux espèces à l’état larvaire révèle que certaines unités (mandibule par exemple) sont très similaires dans leur forme tandis que d’autres (neurocrâne, unité « suspensorium et opercule » et le prémaxillaire) présentent une forme déjà dissemblable. Cependant, la similarité observée laisse clairement supposer que ces pièces sont sujettes aux mêmes contraintes de prise de nourriture : leurs formes permettraient de les considérer comme des « ram-feeders » se nourrissant du même type de proie. Au cours de leur croissance et de la colonisation du récif, la différenciation des entités squelettiques entre chaque espèce se renforce, permettant ainsi à chacune de s’installer progressivement dans sa niche écologique. Les différences entre les larves et les adultes paraissent liées au moins aux contraintes écologiques. [less ▲]

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