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See detailSchizophrénie et psychopathie : Analyse des difficultés d’objectivation diagnostique à partir de la PCL-R
Matteucci, Marie; Englebert, Jérôme ULg; De Page, Louis et al

Poster (2017, May 20)

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See detailDu définitif sur du provisoire...
Englebert, Jérôme ULg; Follet, Valérie

Conference (2017, May 18)

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See detailRadiohead and Prog Rock
Delville, Michel ULg

Conference (2017, May 18)

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See detailApplication of wavelet transforms to geosciences: Extraction of functional and frequential information
Deliège, Adrien ULg

Doctoral thesis (2017)

It is now well-known that there exist functions that are continuous but nowhere differentiable. Still, it appears that some of them are less “irregular” than others. The pointwise regularity of a function ... [more ▼]

It is now well-known that there exist functions that are continuous but nowhere differentiable. Still, it appears that some of them are less “irregular” than others. The pointwise regularity of a function can be characterized by its Hölder exponent at each point. For the sake of practicability, it is more appropriate to determine the “size” of the sets of points sharing a same exponent, through their Hausdorff measure. By doing so, one gets the multifractal spectrum of a function, which characterizes in particular its monofractal or multifractal nature. The first part of this work is based on the so-called “wavelet leaders method” (WLM), recently developed in the context of multifractal analysis, and aims at its application to concrete situations in geosciences. First, we present the WLM and we insist particularly on the major differences between theory and practice in its use and in the interpretation of the results. Then, we show that the WLM turns out to be an efficient tool for the analysis of Mars topography from a unidimensional and bidimensional point of view; the first approach allowing to recover information consistent with previous works, the second being new and highlighting some areas of interest on Mars. Then, we study the regularity of temperature signals related to various climate stations spread across Europe. In a first phase, we show that the WLM allows to detect a strong correlation with pressure anomalies. Then we show that the Hölder exponents obtained are directly linked to the underlying climate and we establish criteria that compare them with their climate characteristics as defined by the Köppen-Geiger classification. On the other hand, the continuous version of the wavelet transform (CWT), developed in the context of time-frequency analysis, is also studied in this work. The objective here is the determination of dominant periods and the extraction of the associated oscillating components that constitute a given signal. The CWT allows, unlike the Fourier transform, to obtain a representation in time and in frequency of the considered signal, which thus opens new research perspectives. Moreover, with a Morlet-like wavelet, a simple reconstruction formula can be used to extract components. Therefore, the second part of the manuscript presents the CWT and focuses mainly on the border effects inherent to this technique. We illustrate the advantages of the zero-padding and introduce an iterative method allowing to alleviate significantly reconstruction errors at the borders of the signals. Then, we study in detail the El Niño Southern Oscillation (ENSO) signal related to temperature anomalies in the Pacific Ocean and responsible for extreme climate events called El Niño (EN) and La Niña (LN). Through the CWT, we distinguish its main periods and we extract its dominant components, which reflect well-known geophysical mechanisms. A meticulous study of these components allows us to elaborate a forecasting algorithm for EN and LN events with lead times larger than one year, which is a much better performance than current models. After, we generalize the method used to extract components by developing a procedure that detects ridges in the CWT. The algorithm, called WIME (Wavelet-Induced Mode Extraction), is illustrated on several highly non-stationary examples. Its ability to recover target components from a given signal is tested and compared with the Empirical Mode Decomposition. It appears that WIME has a better adaptability in various situations. Finally, we show that WIME can be used in real-life cases such as an electrocardiogram and the ENSO signal. [less ▲]

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See detailImplementation of SFC for the quality control of pharmaceuticals
Dispas, Amandine ULg; Andri, Bertyl ULg; Lebrun, Pierre ULg et al

Conference (2017, May 17)

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See detailLe manuel de grammaire latine de Dosithée : quelle méthode d'apprentissge ?
Rochette, Bruno ULg

Conference (2017, May 15)

Contrairement aux autres manuels de grammaire latine destinés aux hellénophones, comme ceux de Charisius, Diomède et Priscien qui travaillent dans la pars Orientis pour des hellénophones, l’Ars grammatica ... [more ▼]

Contrairement aux autres manuels de grammaire latine destinés aux hellénophones, comme ceux de Charisius, Diomède et Priscien qui travaillent dans la pars Orientis pour des hellénophones, l’Ars grammatica de Dosithée est accompagnée d’une traduction grecque. La présence de cette traduction, qui ne concerne toutefois pas toute la grammaire, mais seulement environ la moitié du texte, singularise ce manuel dans la tradition des artes, même si nous ne pouvons exclure que d’autres traités grammaticaux du même type n’aient pas été accompagnés d’une traduction grecque que nous n’aurions pas conservée. Quoi qu’il en soit, le statut de cette traduction est assez difficile à établir. Essentiellement deux questions se posent à son sujet : quel est son auteur, est-ce Dosithée lui-même ou un utilisateur plus tardif (éventuellement dans le monde occidental), et à quoi sert-elle ? Il apparaît clairement que le grec doit aider à la compréhension du latin, non le remplacer. La traduction grecque n’a donc pas une vocation à l’autonomie. Elle n’a de sens qu’en relation avec le latin. La traduction semble se réduire au fur et à mesure que l’on avance dans la grammaire. Il semble que Dosithée attende de l’utilisateur de la grammaire qu’il ait de moins en moins besoin d’aide à mesure qu’il progresse dans l’apprentissage. J’analyse la nature du grec de Dosithée en vue de mieux comprendre la méthode d’apprentissage mise en œuvre dans ce manuel. Bibliographie Bonnet G., Dosithée. Grammaire latine, Paris, CUF, 2005. --, La version grecque de l’Ars de Dosithée, dans L. Basset-Fr. Biville-B. Colombat-P. Swiggers-A. Wouters (éds), Bilinguisme et terminologie grammaticale gréco-latine, Leuven-Paris-Dudley, 2007, p. 191-199. Dickey E., The Authorship of the Greek Version of Dositheus’ Grammar and What it Tells Us about the Grammar’s Original Use, dans R. Ferri-A. Zago (eds), The Latin of the Grammarians. Reflections about Language in the Roman World, Turnhout, 2016, p. 205-235. --, Learning Latin. The Ancient Way. Latin Textbooks from the Ancient World, Cambridge, 2016. Lenoble M. – Swiggers P. – Wouters P., L’enseignement grammatical entre grec et latin : le manuel de Dosithée, P. Desmet-L. Jooken-P. Schmitter-P. Swiggers (eds), The History of Linguistic and Grammatical Praxis. Proceedings of the XIth International Colloquium of the Studienkreis « Geschichte der Sprachwissenschaft » (Leuven, 2nd – 4th July, 1998), Leuven-Paris-Sterling, 2000, p. 3-22. Reichamnn V., Römische Literatur in griechischer Übersetzung, Leipzig, 1943. J. Tolkiehn J., Dosithei Ars Grammatica, Leipzig, 1913. [less ▲]

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See detailBelgian speleothem records Holocene cold events?
Allan, Mohammed ULg; Deliège, Adrien ULg; Nicolay, Samuel ULg et al

Poster (2017, May 12)

Speleothem is now regarded as valuable archive of climatic conditions on the continents, offering a number of advantages relative to other continental climate proxy recorders such as lake sediments and ... [more ▼]

Speleothem is now regarded as valuable archive of climatic conditions on the continents, offering a number of advantages relative to other continental climate proxy recorders such as lake sediments and peat cores. High spatial resolution measurements of Mg, Al, Sr, Ba were realized by using laser-ablation inductively coupled plasma mass spectrometry in the Belgian Pere Noel cave. A stalagmite from the Pere Noel (PN) cave representing 12000 years dated by U/Th method. Trace element variations in speleothem are a reflection of hydrochemical conditions. These changes were interpreted as indications of changes in climate in the Han-sur-Lesse region. The similar patterns found in δ 18O, δ 13C and chemical composition along the Pere Noel stalagmite suggests that trace elements in speleothems have the potential to provide high resolution insights into palaeoclimatic variability during the Holocene. A deeper analysis reveals several periods of significant rapid climate change during the Holocene (at 10.7-9.2 ka, 8.2-7.9 ka, 7.2-6.2 ka, 4.8-4.5 ka, and 3-2.4 ka BP), which are similar to the cold events detected from different natural paleoclimate archivers. A comparison between the geochemical analysis of Père Noël speleothem and solar activity (sunspot number) reveals a significant correlation. Spectral analysis methods reveal common solar periodicities (Gleissberg cycle, de Vries cycle, unnamed 500 year, Eddy cycles, and Hallstatt cycle). The geochemical analyses have the potential to prove that PN speleothem is sensitive to changes in solar activity on centennial and millennial timescales during the Holocene. [less ▲]

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See detailLes constructions relatives du néo-égyptien. Une approche fonctionnelle
Sojic, Nathalie ULg

Doctoral thesis (2017)

Cette dissertation doctorale se propose d’étudier les constructions relatives du néo-égyptien suivant une approche fonctionnelle. Elle offre une première étude large de la relativisation pour cet état de ... [more ▼]

Cette dissertation doctorale se propose d’étudier les constructions relatives du néo-égyptien suivant une approche fonctionnelle. Elle offre une première étude large de la relativisation pour cet état de langue sous l’angle de la variation linguistique. Elle comprend deux grandes parties : les chapitres 1 à 4 sont théoriques, les chapitres 5 à 9 constituent la recherche à proprement parler. Le chapitre 10 conclut l’ensemble. Le premier chapitre (Ch. 1) propose un état de la question des études relatives aux constructions relatives en égyptien ancien et met en avant le manque criant de vision d’ensemble des descriptions et des études proposées jusqu’à présent, tous états de langue confondus. Le chapitre suivant (Ch. 2) définit le cadre théorique dans lequel s’inscrit l’étude, à savoir les bases conceptuelles et terminologiques issues du fonctionnalisme en linguistique. J’y fais également le point sur le recours, en égyptologie, à ces théories. Le troisième chapitre (Ch. 3) est consacré à la délimitation et à la description du corpus, l’accent étant mis sur la variation linguistique (en diachronie et en synchronie dynamique). Je propose ensuite (Ch. 4) un préambule ou un excursus relatif à la définition des « parties du discours », catégories d’après lesquelles sont classées les unités qui composent la phrase. La plupart des études fonctionnelles, dont la présente, ont pour objet l’une de ces catégories. Le cinquième chapitre (Ch. 5) offre une vue d’ensemble des constructions relatives et constructions apparentées en égyptien ancien (ancien, moyen et néo). La description, très générale, vise à rendre compte de leurs principales caractéristiques typologiques et des particularités de la langue étudiée. Le chapitre suivant (Ch. 6) est consacré à l’histoire du système : il en présente les grandes tendances distributionnelles aux stades de la langue antérieurs au néo-égyptien. Cette synthèse montre l’existence de jeux d’oppositions à l’œuvre à une époque donnée et permet d’en constater l’évolution au stade concerné. Dans un autre chapitre, (Ch. 7) j’examine en détail l’expression de la négation dans les relatives. Après y avoir exposé les facteurs de variation spécifique à l’évolution de la négation, je propose une taxonomie fonctionnelle des constructions relatives négatives en néo-égyptien. Plus loin (Ch. 8), je me penche sur l’épineuse question de la valeur sémantique des relatives introduites par nty (« vraies » relatives) et de celles introduites par iw (relatives « virtuelles », c’est-à-dire des circonstancielles fonctionnant comme des relatives). Ma démarche, issue d’une réflexion critique à partir des études menées sur les différents types de relatives dans d’autres langues, m’amène à suggérer que, contrairement à ce qui a été dit pour l’égyptien ancien, leur distribution ne dépend pas uniquement de la définition de l’antécédent ou de la nature du relateur, mais que la valeur sémantique – contingente ou non – de la construction relativisée joue un rôle tout aussi important. Cette nouvelle façon d’aborder le problème permet d’apporter une explication quant à la grammaticalisation observée dans la distribution de ces constructions. L’avant dernier chapitre (Ch. 9) propose une étude approfondie de l’omission du pronom de rappel de l’antécédent dans les relatives du néo-égyptien. J’y recours aux concepts d’échelle d’accessibilité à la relativisation élaborée par Keenan & Comrie (1977), d’échelle d’accessibilité cognitive d’Ariel (1990) et aux travaux d’Hawkins (1999, 2004) relatifs à la structure informationnelle de la phrase complexe. Ce faisant, je définis des contextes particulièrement favorables à une omission, et démontre aussi que ces omissions sont en partie motivées par des facteurs extralinguistiques. Le dernier chapitre (Ch. 10) fait office de conclusion générale. Il fait le point sur l’apport des chapitres précédents et sur les différents types de variations mis en évidence dans cette étude. [less ▲]

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See detailLes problématiques de l'adaptation et de l'intersubjectivité dans la psychothérapie
Englebert, Jérôme ULg

Scientific conference (2017, May 10)

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See detailHunger Art and the Sensorium
Delville, Michel ULg

Conference (2017, May 10)

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See detailThe use of stable isotopes in marine animal trophic ecology
Sturaro, Nicolas ULg; Lepoint, Gilles ULg; Frederich, Bruno ULg et al

Conference (2017, May 05)

Stable isotope analysis has been recognised as a useful tool for studying animal diet, identifying trophic relationships, and delineating food web structures as well as their alteration by human ... [more ▼]

Stable isotope analysis has been recognised as a useful tool for studying animal diet, identifying trophic relationships, and delineating food web structures as well as their alteration by human activities. Over the past decade, the number of studies using stable isotopes of carbon and nitrogen in marine trophic ecology has increased rapidly as technological advancements greatly facilitate their use. This tool is now among the most popular in ecology and several fields of investigations have developed, including the extension of analyses to more ‘difficult’ stable isotope ratio measurements such as sulfur, the use of isotope mixing models, and the creation of compound-specific stable isotope analysis. Here, we present three case studies taken from our own investigations and previously published literature. The first investigates seagrass detritus ecosystem in which the coexistence of a rich number of species of crustacean raises the question of whether trophic diversity exist among these species. The second examines the feeding habits of coral reef fish and explores whether habitat choice on the reef and their behaviour emerges as good predictors of diet. The third presents the potential use of stable isotope analysis in studying the nutrition of scleractinian corals, which are complex symbiotic organisms that usually present both autotrophic and heterotrophic pathways. This tool has enhanced our understanding of coral species biology, yet it remains underused. Overall, we aim to provide initial insights into stable isotope analysis for illustrating their utility and potential applications to better understand food web structures and species diet in the waters around Taiwan. [less ▲]

See detailTo be plastic is fantastic: delineate coral species niches for assessing their tolerance to changes
Denis, Vianney; Sturaro, Nicolas ULg; Yang, Shan-Hua et al

Conference (2017, May 05)

Climatic and anthropogenic disturbances alter coral reefs by reconfiguring existing coral assemblages. Surviving species are selected by the new environment based on particular traits that they may ... [more ▼]

Climatic and anthropogenic disturbances alter coral reefs by reconfiguring existing coral assemblages. Surviving species are selected by the new environment based on particular traits that they may exhibit, with the plasticity in traits defining ecological strategies associated with contrasting degrees of tolerance to changes. In this process, specialists are expected to tolerate few changes to the environmental conditions and are restricted to specific habitat, while generalists can cope with a wider range of environmental conditions by readjusting traits according to the habitat’s features. Ecological strategies in corals have been exclusively defined according to species’ trait averages, irrespective of individual variations. Challenges representing the acquisition and use of energy have also tended to be oversimplified, specifically by the choice of easy traits in the absence of strong scientific evidence. In this study, we propose a re-examination of strategies in scleractinian corals by focusing on the intraspecific variation of traits. We will investigate how the characteristics of a given species niche can help coral species to tolerate changes. Our multidisciplinary approach will focus on three major characteristics of the coral holobiont (its physiology, trophic ecology, and associated microbiome) which together can define the ecological plasticity of species. This work is of tremendous importance for enhancing the understanding of coral response to environmental changes and for ensuring functions as well as the services of this ecosystem to future generations. [less ▲]

See detailUnusually high sea ice cover influences resource use by benthic invertebrates in coastal Antarctica
Michel, Loïc ULg; Dubois, Philippe; Eleaume, Marc et al

Conference (2017, May 04)

Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice ... [more ▼]

Antarctica currently undergoes strong and contrasted impacts linked with climate change. While the West Antarctic Peninsula is one of the most rapidly warming regions in the world, resulting in sea ice cover decrease, the sea ice cover of East Antarctica unexpectedly tends to increase, possibly in relation with changes in atmospheric circulation. Changes in sea ice cover are likely to influence benthic food web structure through modifications of benthic-pelagic coupling, disruption of benthic production and/or modifications of benthic community structure (i.e. resource availability for benthic consumers). Here, we studied shallow (0-20 m) benthic food web structure on the coasts of Petrels Island (Adélie Land, East Antarctica) during an event of unusually high spatial and temporal (two successive austral summers without seasonal break-up) sea ice cover. Using stable isotope ratios of C and N and the SIAR mixing model, we examined importance of 4 organic matter sources (benthic macroalgae, benthic biofilm, sympagic algae, suspended particulate organic matter) for nutrition of dominant primary consumers and omnivores. 14 invertebrate taxa including sessile and mobile polychaetes, gastropods, bivalves, sea stars, sea urchins and sea cucumbers were studied. Our results indicate that most benthic invertebrates predominantly relied on sympagic algae. Despite its very high abundance, trophic role of benthic biofilm seemed limited. However, interpretation of data was complicated by the peculiar ecophysiological features of Antarctic invertebrates, whose very low metabolic rates could be associated to low isotopic turnover and long time to reach isotopic equilibrium with their food items. Resource use by consumers from Adélie Land markedly differed from literature data about invertebrate diet in coastal Antarctica, suggesting 1) important influence of increased sea ice cover on benthic food web structure and 2) high spatial and/or temporal variation in the feeding habits of studied organisms, likely linked with a high degree of trophic plasticity. Our results provide insights about how Antarctic benthic consumers, which have evolved in an extremely stable environment, might adapt their feeding habits in response to sudden man-driven changes in environmental conditions and trophic resource availability. [less ▲]

See detailQuantifying coral colony morphology to assess their roles in ecosystem processes
Chen, Qi; Yang, Emma; Sturaro, Nicolas ULg et al

Poster (2017, May 04)

Colony morphology is among the best predictors of the scleractinian coral’s function in the reef ecosystem. However, morphological traits are categorical and to convert this information into a ... [more ▼]

Colony morphology is among the best predictors of the scleractinian coral’s function in the reef ecosystem. However, morphological traits are categorical and to convert this information into a quantitative value remains a real challenge to quantify the influence of this parameter on ecosystem processes. Recently, the ratio between colony mass and surface area (CMA) has been proposed to represent a suitable proxy of species morphologies and their growth. Hypothetically, CMA could be used to assess a broad range of biological, ecological, and evolutionary processes in coral reef ecosystem. Here, we propose to test CMA as a predictor of coral morphology and focus on the intraspecific variation of this parameter. We used historical coral collection from the Museum of Zoology (National Taiwan University) and our own specimens collected from contrasting environments to establish a database of coral models using a high-resolution David 3D scanner. From these models, we extracted surface area and volume of the coral colonies. Colony mass was measured on a Mark S Bel balance. CMA was compared for its power in predicting species morphology with other traits such as skeleton density. Eventually, we tested the use of CMA at an intraspecific level to detect plasticity in growth rate. Our 3D models are available online (http://www.dipintothereef.com/corals.html) and constitute a valuable resource for estimating the roles of corals in the ecosystem. [less ▲]

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See detailIdentification of non-stationary dynamical systems using multivariate ARMA models
Bertha, Mathieu ULg; Golinval, Jean-Claude ULg

in Mechanical Systems and Signal Processing (2017), 88

This paper is concerned by the modal identification of time-varying mechanical systems. Based on previous works about autoregressive moving average models in vector form (ARMAV) for the modal ... [more ▼]

This paper is concerned by the modal identification of time-varying mechanical systems. Based on previous works about autoregressive moving average models in vector form (ARMAV) for the modal identification of linear time invariant systems, and time-varying autoregressive moving average models (TV-ARMA) for the identification of nonstationary systems, a time-varying ARMAV (TV-ARMAV) model is presented for the multivariate identification of time-varying systems. It results in the identification of not only the time-varying poles of the system but also of its respective time-varying mode shapes. The method is applied on a time-varying structure composed of a beam on which a mass is moving. [less ▲]

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See detailIn vitro biphasic dissolution tests and their suitability for establishing in vitro-in vivo correlations: A historical review
Pestieau, Aude ULg; Evrard, Brigitte ULg

in European Journal of Pharmaceutical Sciences (2017), 102

For many decades, one of the most critical issues in the pharmaceutical industry has been the poor solubility of some drugs. Indeed, a prerequisite for drug absorption is the presence of dissolved drug at ... [more ▼]

For many decades, one of the most critical issues in the pharmaceutical industry has been the poor solubility of some drugs. Indeed, a prerequisite for drug absorption is the presence of dissolved drug at the absorption site and this can be challenging for compounds with low aqueous solubility such as BCS class II (low solubility, high permeability) and IV (low solubility, low permeability) compounds. If the development of oral delivery formulations of these compounds is frequently challenging to formulation scientists in the pharmaceutical industry, the in vitro evaluation of these new formulations is also a great challenge. One alternative approach to overcome the problems encountered with conventional dissolution methods is the use of biphasic dissolution systems. This review provides an overview of the origin and the evolution over time of the biphasic systems and the growing interest among scientists regarding their suitability for establishing in vitro-in vivo correlations. The evolution of these systems and their applications from the 1960s to the present day, such as in system variants and improvements, analysis of complex formulations, discriminatory power, bio-relevance, precipitation and supersaturation visualization, etc. will be discussed. [less ▲]

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