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See detailBreakdown of within- and between-network resting state functional magnetic resonance imaging connectivity during propofol-induced loss of consciousness.
Boveroux, Pierre ULg; Vanhaudenhuyse, Audrey ULg; Bruno, Marie-Aurélie ULg et al

in Anesthesiology (2010), 113(5), 1038-53

BACKGROUND: Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes ... [more ▼]

BACKGROUND: Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes during pharmacological modulation of the level of consciousness. METHODS: Low-frequency spontaneous blood oxygen level-dependent fluctuations were measured in 19 healthy volunteers during wakefulness, mild sedation, deep sedation with clinical unconsciousness, and subsequent recovery of consciousness. RESULTS: Propofol-induced decrease in consciousness linearly correlates with decreased corticocortical and thalamocortical connectivity in frontoparietal networks (i.e., default- and executive-control networks). Furthermore, during propofol-induced unconsciousness, a negative correlation was identified between thalamic and cortical activity in these networks. Finally, negative correlations between default network and lateral frontoparietal cortices activity, present during wakefulness, decreased proportionally to propofol-induced loss of consciousness. In contrast, connectivity was globally preserved in low-level sensory cortices, (i.e., in auditory and visual networks across sedation stages). This was paired with preserved thalamocortical connectivity in these networks. Rather, waning of consciousness was associated with a loss of cross-modal interactions between visual and auditory networks. CONCLUSIONS: Our results shed light on the functional significance of spontaneous brain activity fluctuations observed in functional magnetic resonance imaging. They suggest that propofol-induced unconsciousness could be linked to a breakdown of cerebral temporal architecture that modifies both within- and between-network connectivity and thus prevents communication between low-level sensory and higher-order frontoparietal cortices, thought to be necessary for perception of external stimuli. They emphasize the importance of thalamocortical connectivity in higher-order cognitive brain networks in the genesis of conscious perception. [less ▲]

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See detailLe contrat d'échange et la loi Breyne, note sous Civ. Gand, 7 avril 2009
Kohl, Benoît ULg

in Entreprise et le Droit (L') = Tijdschrift voor Aannemingsrecht (2010)

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See detailLocal Cooperativity in an Amyloidogenic State of Human Lysozyme Observed at Atomic Resolution.
Dhulesia, A.; Cremades, N.; Kumita, J. R. et al

in Journal of the American Chemical Society (2010)

The partial unfolding of human lysozyme underlies its conversion from the soluble state into amyloid fibrils observed in a fatal hereditary form of systemic amyloidosis. To understand the molecular ... [more ▼]

The partial unfolding of human lysozyme underlies its conversion from the soluble state into amyloid fibrils observed in a fatal hereditary form of systemic amyloidosis. To understand the molecular origins of the disease, it is critical to characterize the structural and physicochemical properties of the amyloidogenic states of the protein. Here we provide a high-resolution view of the unfolding process at low pH for three different lysozyme variants, the wild-type protein and the mutants I56T and I59T, which show variable stabilities and propensities to aggregate in vitro. Using a range of biophysical techniques that includes differential scanning calorimetry and nuclear magnetic resonance spectroscopy, we demonstrate that thermal unfolding under amyloidogenic solution conditions involves a cooperative loss of native tertiary structure, followed by progressive unfolding of a compact, molten globule-like denatured state ensemble as the temperature is increased. The width of the temperature window over which the denatured ensemble progressively unfolds correlates with the relative amyloidogenicity and stability of these variants, and the region of lysozyme that unfolds first maps to that which forms the core of the amyloid fibrils formed under similar conditions. Together, these results present a coherent picture at atomic resolution of the initial events underlying amyloid formation by a globular protein. [less ▲]

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See detailStructure and properties of a complex of alpha-synuclein and a single-domain camelid antibody.
De Genst, Erwin J; Guilliams, Tim; Wellens, Joke et al

in Journal of Molecular Biology (2010), 402(2), 326-43

The aggregation of the intrinsically disordered protein alpha-synuclein to form fibrillar amyloid structures is intimately associated with a variety of neurological disorders, most notably Parkinson's ... [more ▼]

The aggregation of the intrinsically disordered protein alpha-synuclein to form fibrillar amyloid structures is intimately associated with a variety of neurological disorders, most notably Parkinson's disease. The molecular mechanism of alpha-synuclein aggregation and toxicity is not yet understood in any detail, not least because of the paucity of structural probes through which to study the behavior of such a disordered system. Here, we describe an investigation involving a single-domain camelid antibody, NbSyn2, selected by phage display techniques to bind to alpha-synuclein, including the exploration of its effects on the in vitro aggregation of the protein under a variety of conditions. We show using isothermal calorimetric methods that NbSyn2 binds specifically to monomeric alpha-synuclein with nanomolar affinity and by means of NMR spectroscopy that it interacts with the four C-terminal residues of the protein. This latter finding is confirmed by the determination of a crystal structure of NbSyn2 bound to a peptide encompassing the nine C-terminal residues of alpha-synuclein. The NbSyn2:alpha-synuclein interaction is mediated mainly by side-chain interactions while water molecules cross-link the main-chain atoms of alpha-synuclein to atoms of NbSyn2, a feature we believe could be important in intrinsically disordered protein interactions more generally. The aggregation behavior of alpha-synuclein at physiological pH, including the morphology of the resulting fibrillar structures, is remarkably unaffected by the presence of NbSyn2 and indeed we show that NbSyn2 binds strongly to the aggregated as well as to the soluble forms of alpha-synuclein. These results give strong support to the conjecture that the C-terminal region of the protein is not directly involved in the mechanism of aggregation and suggest that binding of NbSyn2 could be a useful probe for the identification of alpha-synuclein aggregation in vitro and possibly in vivo. [less ▲]

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See detailMieux traiter le diabète : combattre l’inertie et améliorer l’adhésion au traitement.
SCHEEN, André ULg; PHILIPS, Jean-Christophe ULg; PAQUOT, Nicolas ULg

in Association belge du diabète (2010), 53

Le diabète est une maladie chronique par excellence. Comme beaucoup d’autres maladies chroniques, le diabète, qu’il soit de type 1 ou plus encore de type 2, est d’origine complexe, combinant l’infl uence ... [more ▼]

Le diabète est une maladie chronique par excellence. Comme beaucoup d’autres maladies chroniques, le diabète, qu’il soit de type 1 ou plus encore de type 2, est d’origine complexe, combinant l’infl uence de facteurs génétiques et environnementaux. Le but du traitement est de corriger au mieux l’hyperglycémie chronique, mais aussi d’autres facteurs de risque (hypertension artérielle, hypercholestérolémie,…), de façon à prévenir la survenue de complications, garantir une bonne qualité de vie et améliorer l’espérance de vie. [less ▲]

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See detailZero Energy Retrofit Case Study of a Chalet in Ain-Sukhna, EGYPT
Attia, Shady ULg

in Conference proceedings of American Solar Energy Society - 2010 (2010)

This paper presents the results of combined economic and computational study of different integrated passive and active design strategies for the Red Sea Coastline of Egypt. A chalet, located in Ain ... [more ▼]

This paper presents the results of combined economic and computational study of different integrated passive and active design strategies for the Red Sea Coastline of Egypt. A chalet, located in Ain-Sukhna is selected as a case study for the zero energy retrofit. The aim of the study is to investigate the potential of achieving thermal comfort and delivering electrical demands for existing buildings on site. The Red Sea Coastline of Egypt has a semi arid climate with an annual total irradiation above 2409 bankable kWh/m2 per year with approximately 3300 hours of full sunshine. Moreover, the annual monthly averages of wind speed in this region range from 5.0 to 7.1 m/s. Therefore, different passive and active design strategies are discussed and compared to reach an annual net zero energy demand for the existing building stock. In order to achieve zero energy retrofit certain strategies are examined. For example, internal loads reduction, envelope retrofitting in addition to the installation of solar water heater, photovoltaic and small-scale wind turbine. Based on a month-by–month demand analysis, internal loads and envelope performance are analyzed in order to explore the existing economical potential. Simulation software TRNSYS is used to predict the annual net zero energy performance for a chalet at Ain-Sukhna. The final result of this study compares the potential and constraints of each strategy and rank them based on economical feasibility. For the considered location and weather conditions the Chalet can provide thermal comfort for occupants and meets the zero energy objectives. The research also proofs that some strategies applied for retrofitting are economical rewarding with a payback period ranging from 2 to 7 years. [less ▲]

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See detailExperimental investigation of the effect of flip bucket splitters on plunge pool geometry
Erpicum, Sébastien ULg; Archambeau, Pierre ULg; Dewals, Benjamin ULg et al

in RWTH - IWW (Ed.) Mitteilungen - 15. Deutsches Talsperrensymposium - Talsperren im Wandel (2010)

Flip buckets are common hydraulic structures aiming at deflecting high velocity flows to a free jet trajectory. Systematic experimental tests have been performed to assess the influence on energy ... [more ▼]

Flip buckets are common hydraulic structures aiming at deflecting high velocity flows to a free jet trajectory. Systematic experimental tests have been performed to assess the influence on energy dissipation and the plunge pool geometry of varied repartitions of splitters along the flip bucket width. In particular, it is shown that some configurations can create more erosion than a continuous channel without flip bucket. [less ▲]

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See detailDeveloping Countries facing Global Warming: a Post-Kyoto Assessment. Round-table Debate
Ozer, Pierre ULg

in De Dapper, Morgan; Swinne, Danielle; Ozer, Pierre (Eds.) Developing Countries facing Global Warming: a Post-Kyoto Assessment. (2010)

This paper reports the results of a round-table debate organized by the Royal Academy for Overseas Sciences (RAOS) on Developing Countries facing Global Warming: a Post-Kyoto Assessment (Brussels, 13 June ... [more ▼]

This paper reports the results of a round-table debate organized by the Royal Academy for Overseas Sciences (RAOS) on Developing Countries facing Global Warming: a Post-Kyoto Assessment (Brussels, 13 June, 2009) to highlight the view of developing countries on adaptation to and mitigation of climate change. The participants convened to discuss the various aspects of climate change impacts and adaptation in developing countries preceding the Copenhagen Conference (UNFCCC COP 15) in December 2009. Here, we summarize the point of view of the two invited speakers representing developing countries. [less ▲]

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See detailClean Development Mechanisms (CDM) and Sustainable Development in South Countries
Ozer, Pierre ULg

in De Dapper, Morgan; Swinne, Danielle; Ozer, Pierre (Eds.) Developing Countries facing Global Warming: a Post-Kyoto Assessment. (2010)

The Clean Development Mechanism (CDM) allows emission reduction (or emission removal) projects in developing countries to earn Certified Emission Reduction (CER) credits, each equivalent to one tonne of ... [more ▼]

The Clean Development Mechanism (CDM) allows emission reduction (or emission removal) projects in developing countries to earn Certified Emission Reduction (CER) credits, each equivalent to one tonne of CO2. These CERs can be traded and sold, and used by industrialized countries to meet a part of their emission reduction targets under the Kyoto Protocol. The mechanism stimulates sustainable development and emission reductions, while giving industrialized countries some flexibility in how they meet their emission reduction limitation targets. Accepted projects must qualify through a rigorous and public registration and issuance process designed to ensure real, measurable and verifiable emission reductions that are additional to what would have occurred without the project. Between November 2004 and May 2009, the mechanism has registered 1,653 projects and is anticipated to currently produce CERs amounting to 303 106 tonnes of CO2 equivalent yearly. The mechanism is extremely interesting since it is the first global, environmental investment and credit scheme of its kind, providing a standardized emissions offset instrument. However the geographical distribution of the CDM projects is revealing very large differences in between developing countries since China, India, Brazil and South-Korea totalise 82 % of the CERs while Africa only represents 3,3% of the total. [less ▲]

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See detailOnline least-squares policy iteration for reinforcement learning control
Busoniu, Lucian; Ernst, Damien ULg; De Schutter, Bart et al

in Proceedings of the 2010 American Control Conference (2010)

Reinforcement learning is a promising paradigm for learning optimal control. We consider policy iteration (PI) algorithms for reinforcement learning, which iteratively evaluate and improve control ... [more ▼]

Reinforcement learning is a promising paradigm for learning optimal control. We consider policy iteration (PI) algorithms for reinforcement learning, which iteratively evaluate and improve control policies. State-of-the-art, least-squares techniques for policy evaluation are sample-efficient and have relaxed convergence requirements. However, they are typically used in offline PI, whereas a central goal of reinforcement learning is to develop online algorithms. Therefore, we propose an online PI algorithm that evaluates policies with the so-called least-squares temporal difference for Q-functions (LSTD-Q). The crucial difference between this online least-squares policy iteration (LSPI) algorithm and its offline counterpart is that, in the online case, policy improvements must be performed once every few state transitions, using only an incomplete evaluation of the current policy. In an extensive experimental evaluation, online LSPI is found to work well for a wide range of its parameters, and to learn successfully in a real-time example. Online LSPI also compares favorably with offline LSPI and with a different flavor of online PI, which instead of LSTD-Q employs another least-squares method for policy evaluation. [less ▲]

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See detailLa vignette thérapeutiqu de l'étudiant Diagnostic différentiel étiologique des oedmes
Krzesinski, Jean-Marie ULg

in Revue Médicale de Liège (2010), 65(11), 655-661

Oedema is a frequent disorder and the easily detectable consequence of an increase of fluid located in the interstitial tissue. It could be localized or generalized and related either to a primary ... [more ▼]

Oedema is a frequent disorder and the easily detectable consequence of an increase of fluid located in the interstitial tissue. It could be localized or generalized and related either to a primary disturbance of hemodynamics at the capillary level, due to a modification of the Starling’s law components with secondary water and saline retention, or to a primary retention of salt and water linked to a kidney abnormality. Generalized forms are pitting oedema, most often painless, white, bilateral and symmetric, distributed at the lower part of the body (localisation according to the gravitation law). They are different in their characteristics from localized oedema or lymphoedema which are tough. We propose a diagnostic approach based on medical history, clinical examination which allows a confident medical diagnosis and so an adapted therapy. [less ▲]

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See detailAb initio calculation of H + He+ charge-transfer cross section for plasma physics
Loreau, Jérôme; Sodoga, Komi; Lauvergnat, David et al

in Physical Review. A (2010), 82

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See detailAssessing the Impact of Weather on Traffic Intensity
Cools, Mario ULg; Moons, Elke; Wets, Geert

in Weather, Climate and Society (2010), 2(1), 6068

This paper focuses on the effect of weather conditions on daily traffic intensities (the number of cars passing a specific segment of a road). The main objective is to examination whether or not weather ... [more ▼]

This paper focuses on the effect of weather conditions on daily traffic intensities (the number of cars passing a specific segment of a road). The main objective is to examination whether or not weather conditions uniformly alter daily traffic intensities in Belgium, or in other words whether or not road usage on a particular location determines the size of the impacts of various weather conditions. This general examination is a contribution that allows policymakers to assess the appropriateness of countrywide versus local traffic management strategies. In addition, a secondary goal of this paper is to validate findings in international literature within a Belgian context. To achieve these goals, the paper analyzes the effects of weather conditions on both upstream (toward a specific location) and downstream (away from a specific location) traffic intensities at three traffic count locations typified by a different road usage. Perhaps the most interesting results of this study for policymakers are the heterogeneity of the weather effects between different traffic count locations, and the homogeneity of the weather effects on upstream and downstream traffic at specific locations. The results also indicate that snowfall, rainfall, and wind speed diminish traffic intensity, and high temperatures increase traffic intensity. Further generalizations of the findings might be possible by studying weather impacts on local roads and by shifting the focus of research toward travel behavior. [less ▲]

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See detailEthique de l’information clinique et consentement des patients
Jamoulle, Marc ULg

Report (2010)

Le projet de recherche REGM (Enregistrement de morbidité) du Service Public Fédéral Belge de la Santé Publique (SPF-SP) se propose d’étudier la faisabilité de la constitution de base de données de ... [more ▼]

Le projet de recherche REGM (Enregistrement de morbidité) du Service Public Fédéral Belge de la Santé Publique (SPF-SP) se propose d’étudier la faisabilité de la constitution de base de données de morbidité en médecine générale en Belgique. Dans ce cadre la question du consentement des patients (et des médecins) est bien sur centrale et préalable à tous développements ultérieurs. On examine ici les conditions de réalisations d’un tel consentement du patient et les différentes formes qu’il peut prendre. Des expériences sont relatées qui permettent de prendre la mesure des enjeux. Une recommandation est formulée pour un consentement différencié, distinct et dynamique qui se fait l’écho de la relation de confiance médecin patient dont il est la traduction. [less ▲]

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See detailCortisol awakening response (CAR)’s flexibility leads to larger and more consistent associations with psychological factors than CAR magnitude
Mikolajczak, M.; Quoidbach, Jordi ULg; Vanootighem, Valentine ULg et al

in Psychoneuroendocrinology (2010)

The cortisol awakening response (CAR) is increasingly recognized as a potential biological marker of psychological and physical health status. Yet, the CAR literature is replete with contradictory results ... [more ▼]

The cortisol awakening response (CAR) is increasingly recognized as a potential biological marker of psychological and physical health status. Yet, the CAR literature is replete with contradictory results: both supposedly protective and vulnerability psychosocial factors have been associated with both increased and decreased CAR. In this study, we tested the hypothesis that the CAR flexibility would be a better indicator of psychological status than CAR magnitude. Forty-two men measures of happiness, perceived stress and neuroticism, and took saliva samples immediately on awakening, then at 15, 30, 45 and 60 min post-awakening on three study days (i.e., Sunday, Monday and Tuesday). When considering the CAR magnitude, our effects perfectly reflect the inconsistencies previously observed in the literature (i.e., the main effects of the psychological predictors are not consistent with each other, and the effect of one predictor on a given day contradicts the effect of the same predictor on another day). However, considering the CAR flexibility leads to a fully consistent pattern: protective factors (i.e., high happiness, low stress, low neurotiscim) are associated with a flexible CAR (i.e., lower CAR during weekends compared to workdays) whereas vulnerability factors (i.e., low happiness, high stress, high neurotiscim) are associated with a stiff CAR (i.e., same magnitude during weekends and workdays). We conclude that considering the CAR flexibility (e.g., between weekends and workdays) rather than the traditional CAR magnitude might be a way to understand the apparent conflicts in the CAR literature. [less ▲]

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See detailCrown rot of banana: Preharvest factors involved in postharvest disease development and integrated control methods
Lassois, Ludivine ULg; Jijakli, Haissam ULg; Chillet, M. et al

in Plant Disease (2010), 94(6), 648-658

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See detailOn the Sets of Real Numbers Recognized by Finite Automata in Multiple Bases
Boigelot, Bernard ULg; Brusten, Julien ULg; Bruyère, Véronique

in Logical Methods in Computer Science (2010), 6(1), 1-17

This article studies the expressive power of finite automata recognizing sets of real numbers encoded in positional notation. We consider Muller automata as well as the restricted class of weak ... [more ▼]

This article studies the expressive power of finite automata recognizing sets of real numbers encoded in positional notation. We consider Muller automata as well as the restricted class of weak deterministic automata, used as symbolic set representations in actual applications. In previous work, it has been established that the sets of numbers that are recognizable by weak deterministic automata in two bases that do not share the same set of prime factors are exactly those that are definable in the first order additive theory of real and integer numbers. This result extends Cobham's theorem, which characterizes the sets of integer numbers that are recognizable by finite automata in multiple bases. In this article, we first generalize this result to multiplicatively independent bases, which brings it closer to the original statement of Cobham's theorem. Then, we study the sets of reals recognizable by Muller automata in two bases. We show with a counterexample that, in this setting, Cobham's theorem does not generalize to multiplicatively independent bases. Finally, we prove that the sets of reals that are recognizable by Muller automata in two bases that do not share the same set of prime factors are exactly those definable in the first order additive theory of real and integer numbers. These sets are thus also recognizable by weak deterministic automata. This result leads to a precise characterization of the sets of real numbers that are recognizable in multiple bases, and provides a theoretical justification to the use of weak automata as symbolic representations of sets. [less ▲]

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See detailImplicit Real Vector Automata
Boigelot, Bernard ULg; Brusten, Julien ULg; Degbomont, Jean-François ULg

in Electronic Proceedings in Theoretical Computer Science (2010), 39

This paper addresses the symbolic representation of non-convex real polyhedra, i.e., sets of real vectors satisfying arbitrary Boolean combinations of linear constraints. We develop an original data ... [more ▼]

This paper addresses the symbolic representation of non-convex real polyhedra, i.e., sets of real vectors satisfying arbitrary Boolean combinations of linear constraints. We develop an original data structure for representing such sets, based on an implicit and concise encoding of a known structure, the Real Vector Automaton. The resulting formalism provides a canonical representation of polyhedra, is closed under Boolean operators, and admits an efficient decision procedure for testing the membership of a vector. [less ▲]

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See detailSemantic Hyperpriming in Normal Aging: A Consequence of Instructions?
Stefaniak, Nicolas ULg; Meulemans, Thierry ULg; Willems, Sylvie ULg

in Neuropsychology, Development, and Cognition. Section B, Aging, Neuropsychology and Cognition (2010), 17(5), 615-632

Semantic hyperpriming has consistently been found in normal aging. However, <br />because the standard instructions to test semantic priming are generally ambiguous <br />(focusing on both accuracy and ... [more ▼]

Semantic hyperpriming has consistently been found in normal aging. However, <br />because the standard instructions to test semantic priming are generally ambiguous <br />(focusing on both accuracy and speed), it is difficult to account for hyperpriming in <br />older adults. By using the direct and mediated priming paradigms, this study investigates <br />whether older adults’ response mode at testing may explain hyperpriming. First, we <br />show that, under identical conditions, inducing a response mode that favors speed leads <br />to greater priming effects in older adults. The pattern of results is similar to what is <br />observed under standard instructions. Second, prompting a response mode that favors <br />accuracy leads to greater priming effects in younger adults. We discuss various explanations <br />for these findings and conclude, in accordance with the Ratcliff, Thapar, <br />Gomez, and McKoon (2004a) diffusion model, that hyperpriming in normal aging is <br />contingent on older adults’ response mode at testing. [less ▲]

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See detailIntegrated control of crown rot of banana with Candida oleophila strain O, calcium chloride and modified atmosphere packaging
Bastiaanse, H.; de Lapeyre de Bellaire, Luc; Lassois, Ludivine ULg et al

in Biological Control (2010), 53

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