Publications ORBi OA     Results 26541-26560 of 52973.   1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333   Le Comité France-Amérique et l’Alliance française à MontréalDozo, Björn-Olav in Luneau, Marie-Pier; Mellot, Jean-Dominique; Montreuil, Sophie (Eds.) et al Passeurs d'histoire(s). Figures des relations France-Québec en histoire du livre (2010)Detailed reference viewed: 39 (2 ULg) Soil surface water content estimation by full-waveform GPR signal inversion in the presence of thin layersMinet, Julien ; Lambot, Sébastien; Slob, Evert C. et alin IEEE Transactions on Geoscience and Remote Sensing (2010), 48We analyzed the effect of shallow thin layers on the estimation of soil surface water content using full-waveform inversion of off-ground ground penetrating radar (GPR) data. Strong dielectric contrasts ... [more ▼]We analyzed the effect of shallow thin layers on the estimation of soil surface water content using full-waveform inversion of off-ground ground penetrating radar (GPR) data. Strong dielectric contrasts are expected to occur under fast wetting or drying weather conditions, thereby leading to constructive and destructive interferences with respect to the surface reflection. First, synthetic GPR data were generated and subsequently inverted considering different thin-layer model configurations. The resulting inversion errors when neglecting the thin layer were quantified, and then, the possibility to reconstruct these layers was investigated. Second, laboratory experiments reproducing some of the numerical experiments configurations were conducted to assess the stability of the inverse solution with respect to actual measurement and modeling errors. Results showed that neglecting shallow thin layers may lead to significant errors on the estimation of soil surface water content ($\Delta\theta$ > 0.03 $m^3/m^3$), depending on the contrast. Accounting for these layers in the inversion process strongly improved the results, although some optimization issues were encountered. In the laboratory, the proposed full-waveform method permitted to reconstruct thin layers with a high resolution up to 2 cm and to retrieve the soil surface water content with an rmse less than 0.02 $m^3/m^3$, owing to the full-waveform inverse modeling. These results suggest that the proposed GPR approach is promising for field-scale mapping of soil surface water content of nondispersive soils with low electrical conductivity and for instances when soil layering is encountered. [less ▲]Detailed reference viewed: 62 (0 ULg) Instability and Overshoots of Solutions For A Class of Homogeneous Hybrid Systems By Lyapunov-like AnalysisForni, Fulvio ; Teel, Andrewin 49th IEEE Conference on Decision and Control (cdc 2010) (2010)For a class of homogeneous hybrid systems we present a generalization to the hybrid systems framework of Chetaev's theorem and we propose a set of Lyapunov-like conditions for studying instability of the ... [more ▼]For a class of homogeneous hybrid systems we present a generalization to the hybrid systems framework of Chetaev's theorem and we propose a set of Lyapunov-like conditions for studying instability of the point x e = 0 and overshoots of solutions (namely when the norm of the solution vector x at some time instant exceeds the norm of the initial condition of x). Based on these results, we design a sum of squares algorithm that constructs a suitable Lyapunov-like function to fulfill such conditions. [less ▲]Detailed reference viewed: 17 (7 ULg) Stability For A Class of Homogeneous Hybrid Systems By Annular Lyapunov AnalysisForni, Fulvio ; Teel, Andrewin 49th IEEE Conference on Decision and Control (cdc 2010) (2010)For a class of homogeneous hybrid systems we present a set of annular Lyapunov-like conditions for inferring global pre-asymptotic stability of systems. Then, we prove that such conditions are mild ... [more ▼]For a class of homogeneous hybrid systems we present a set of annular Lyapunov-like conditions for inferring global pre-asymptotic stability of systems. Then, we prove that such conditions are mild, namely, that each globally pre-asymptotically stable system must satisfy them. Based on these results, we design a sum of squares algorithm that constructs a suitable Lyapunov-like function to fulfill such annular conditions. Finally, based on recent results on homogeneous approximations of hybrid systems, we point out that such conditions can also be used to deduce local pre-asymptotic stability for a wider class of hybrid systems. [less ▲]Detailed reference viewed: 15 (3 ULg) Gain-scheduled, model-based anti-windup for LPV systemsForni, Fulvio ; Galeani, Sergioin Automatica (2010), 46(1), 222-225The aim of this paper is to show that a recently proposed technique for anti-windup control of exponentially unstable plants can be easily extended to solve the corresponding robust anti-windup problem ... [more ▼]The aim of this paper is to show that a recently proposed technique for anti-windup control of exponentially unstable plants can be easily extended to solve the corresponding robust anti-windup problem for linear parameter varying systems, for which the time varying parameters are measured online. The proposed technique is minimally conservative with respect to the size of the resulting operating region (which coincides, up to an arbitrarily small quantity, with the largest set on which asymptotic stability can be guaranteed for the considered plant with the given saturation level and uncertainty characteristics), and is not limited to plants having only small uncertainties or being open-loop stable. [less ▲]Detailed reference viewed: 63 (6 ULg) An almost Anti-Windup scheme for plants with magnitude, rate and curvature saturationForni, Fulvio ; Galeani, Sergio; Zaccarian, ucain American Control Conference (ACC 2010) (2010)We address the anti-windup augmentation problem for plants with saturations on the magnitude, rate and curvature of the control input. To this aim, given an unconstrained closed-loop, we generate a ... [more ▼]We address the anti-windup augmentation problem for plants with saturations on the magnitude, rate and curvature of the control input. To this aim, given an unconstrained closed-loop, we generate a slightly modified strictly proper controller for which the derivatives of the control signal are available and we solve the anti-windup problem for this modified control scheme (namely, an almost anti-windup for the original closed-loop). Based on this “almost” approach, we revisit an existing Model Recovery anti-windup solution for rate and magnitude saturated plants and then we extend the results to the case of rate, magnitude and curvature saturation, by providing a Model Recovery solution to this additional problem. An example illustrates the peculiarities and the effectiveness of the proposed solutions. [less ▲]Detailed reference viewed: 22 (0 ULg) Hot and cold contrasts in high resolution Tc-99m planar scintigraphy: a survey of fifty-two camera heads using the PICKER thyroid phantomSeret, Alain in Physica Medica : An International Journal Devoted to the Applications of Physics to Medicine and Biology : Official Journal of the Italian Association of Biomedical Physics (AIFB) [=PM] (2010), 26(3), 166-172This study aimed at comparing the sensitivity and hot and cold contrasts obtained when imaging the Picker thyroid phantom using gamma cameras fitted with either their ultra-high or high-resolution low ... [more ▼]This study aimed at comparing the sensitivity and hot and cold contrasts obtained when imaging the Picker thyroid phantom using gamma cameras fitted with either their ultra-high or high-resolution low energy parallel hole collimator. Seventeen camera models from Elscint, General Electric, Siemens and Sopha Medical Vision were involved in the study for a total of 30 cameras and 52 camera heads. A single operator conducted the study in order to minimize the impact of human factors. The phantom contained about 74 MBq 99mTc and was imaged at 10-cm from the collimator face with the energy window recommended by the camera manufacturer. A total of 1 million counts were accumulated. Hot and cold contrasts were in mean about 0.05 higher when using an ultra-high-resolution than when using a high-resolution low energy collimator. This higher contrast was obtained at the expense of a mean reduction in sensitivity of 30%. In particular, Elscint cameras demonstrated a 30% lower sensitivity whatever the collimator type. The Sopha Medical Vision DST and DSX cameras and the General Electric Magicam camera offered the lowest contrasts among the cameras with a high-resolution collimator. Although this was accompanied by a higher than the mean sensitivity for the DST and DSX, the Magicam demonstrated sensitivity roughly identical to the mean of all the cameras with a high-resolution collimator. [less ▲]Detailed reference viewed: 40 (2 ULg) Synthèse bibliographique : l’écologie chimique des coccinellesDurieux, Delphine ; Verheggen, François ; Vandereycken, Axel et alin Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2010), 14(2), 351-367This paper reviews the chemical ecology of ladybird beetles (Coleoptera: Coccinellidae) to present the role of semiochemicals involved in plant-ladybird, prey-ladybird and predator-ladybird interactions ... [more ▼]This paper reviews the chemical ecology of ladybird beetles (Coleoptera: Coccinellidae) to present the role of semiochemicals involved in plant-ladybird, prey-ladybird and predator-ladybird interactions. Ladybird beetles use these compounds to locate their prey, mate, protect themselves from predation or cannibalism, find a shelter to overwinter or ensure a better survival for their offspring. Thorough studies on ladybird behaviours towards these compounds could lead to their practical implementation in integrated strategies using ladybirds to control pests, like aphids or mealybugs. [less ▲]Detailed reference viewed: 390 (75 ULg) Chilling of carcasses from double muscled cattle: time-temperature evolution and predictive modelling of growth of Listeria monocytogenes and Clostridium perfringensDelhalle, Laurent ; Collignon, Bertrand; Dehard, Sandrine et alPoster (2010)The time/temperature combination during carcass chilling is of concern in order to avoid bacterial growth. The chilling speed is lower in carcasses with high muscular development such as large cattle from ... [more ▼]The time/temperature combination during carcass chilling is of concern in order to avoid bacterial growth. The chilling speed is lower in carcasses with high muscular development such as large cattle from the Belgian Blue breed. Three slaughterhouses were selected for temperature and pH measurements during the chilling process at 6 different days on 4 half carcasses in order to obtain representative data from heavy carcasses with high muscular development. Predictive microbiology was used to evaluate the potential growth of Listeria monocytogenes and Clostridium perfringens on the surface and in the depth of the carcasses. The gamma concept was chosen as secondary model taking into account the effect of temperature, pH and water activity on the selected bacteria during the chilling process. The predicted growth potential of Listeria monocytogenes is influenced by the different environmental conditions of the selected slaughterhouses and could reach 1.4 log CFU/cm² after the chilling process. The potential growth of Clostridium perfringens is limited due to unfavourable conditions during the first hours and to low temperature later. It can be concluded that when the initial level of contaminating bacteria is not excessive the speed at which the carcass is currently chilled is sufficient to limit the growth of these two pathogens and to ensure the product quality. [less ▲]Detailed reference viewed: 48 (17 ULg) Apports et potentialités de l’utilisation de la carte mentale en science politiqueBreux, Sandra; Reuchamps, Min ; Loiseau, Hugoin Transeo Review (2010), (2-3), L’objectif de notre propos est de mettre en évidence les potentiels de l’utilisation de la carte mentale en science politique. Souvent utilisée en psychologie et en géographie, les politologues ont ... [more ▼]L’objectif de notre propos est de mettre en évidence les potentiels de l’utilisation de la carte mentale en science politique. Souvent utilisée en psychologie et en géographie, les politologues ont toutefois rarement recours à cet outil de collecte de l’information dans leurs recherches. En revenant sur les avantages et les limites de l’usage de cet outil en sciences sociales, et en nous basant sur deux études originales, nous montrerons dans quelle mesure la carte mentale peut permettre d’aborder des questions propres à la science politique sous un angle nouveau. [less ▲]Detailed reference viewed: 511 (19 ULg) Le ratage sans gloire. A propos des Martyrs ridicules de Léon CladelDurand, Pascal in Glinoer, Anthony; Brissette, Pascal (Eds.) Bohème sans frontière (2010)Extrait de l'introduction au volume collectif Bohème sans frontière (P. Brissette et A. Glinoer) : « Les Martyrs ridicules qu'étudie ici Pascal Durand vise l'ensemble des clichés et stéréotypes du mythe ... [more ▼]Extrait de l'introduction au volume collectif Bohème sans frontière (P. Brissette et A. Glinoer) : « Les Martyrs ridicules qu'étudie ici Pascal Durand vise l'ensemble des clichés et stéréotypes du mythe [de la bohème] à travers l'histoire d'un provincial monté à Paris, histoire des déboires et de la perte des illusions littéraires non compensées, chez le protagoniste, par les succès momentané dont jouit un Lucien de Rubempré au milieu d'Illusions perdues. Durand interroge les motivations qui ont pu conduire le jeune Cladel à entrer en littérature par cette œuvre anti-bohème, et son préfacier, Baudelaire, à coopter son cadet et son geste irrévérencieux l'année où il entre lui-même, avec quelle ironie, dans la lice académique et brigue le siège de Lacordaire » (p. 14-15). [less ▲]Detailed reference viewed: 100 (33 ULg) Assessment and detection of pain in noncommunicative severely brain-injured patients.Schnakers, Caroline ; Chatelle, Camille ; Majerus, Steve et alin Expert Review of Neurotherapeutics (2010), 10(11), 1725-31Detecting pain in severely brain-injured patients recovering from coma represents a real challenge. Patients with disorders of consciousness are unable to consistently or reliably communicate their ... [more ▼]Detecting pain in severely brain-injured patients recovering from coma represents a real challenge. Patients with disorders of consciousness are unable to consistently or reliably communicate their feelings and potential perception of pain. However, recent studies suggest that patients in a minimally conscious state can experience pain to some extent. Pain monitoring in these patients is hence of medical and ethical importance. In this article, we will focus on the possible use of behavioral scales for the assessment and detection of pain in noncommunicative patients. [less ▲]Detailed reference viewed: 125 (3 ULg) La Sensory Modality Assessment and Rehabilitation Technique (SMART) : une echelle comportementale d'evaluation et de revalidation pour des etats alteres de conscience.Chatelle, Camille ; Schnakers, Caroline ; Bruno, Marie-Aurélie et alin Revue Neurologique (2010), 166(8-9), 675-82INTRODUCTION: Difficulties in detecting bedside signs of consciousness in non-communicative patients still lead to a high rate of misdiagnosis illustrating the need to employ standardized behavioral ... [more ▼]INTRODUCTION: Difficulties in detecting bedside signs of consciousness in non-communicative patients still lead to a high rate of misdiagnosis illustrating the need to employ standardized behavioral assessment scales. STATE OF ART: The Sensory Modality Assessment and Rehabilitation Technique (SMART) is a behavioral assessment scale of consciousness that assesses responses to multimodal sensory stimulation in disorders of consciousness. These stimulations can also be considered to have therapeutic value. PERSPECTIVES: We here review the different components and use of the SMART assessment and discuss its validity, reliability, and robustness in clinical practice. The scale has a high intra- and inter-observer reliability thanks to a detailed procedure description. However, in the absence of objective gold standards in the assessment of consciousness, it is currently difficult to make strong claims about its validity. A comparison between SMART and other standardized and validated coma-scales is proposed. CONCLUSION: In our view, SMART is an interesting tool for monitoring patients with altered states of consciousness subsequent to coma. Currently, we await studies on its concurrent validity as compared to other validated behavioral assessment scales and on the effect of SMART stimulations on patient outcome. [less ▲]Detailed reference viewed: 157 (5 ULg) ASCID : le noyau centrral de douze facteurs expliquant la conduite en éducation thérapeutique du patientLeclercq, Dieudonné in Education Thérapeutique du Patient [=ETP] = Therapeutic Patient Education [=TPE] (2010), 2(2), 213-221Abstract – ASCID: the core of 12 factors that explain behavior in patient education. Introduction: Professionals involved in Patient Education need to have a good understanding of the (numerous) factors ... [more ▼]Abstract – ASCID: the core of 12 factors that explain behavior in patient education. Introduction: Professionals involved in Patient Education need to have a good understanding of the (numerous) factors that affect, in a person, her becoming aware, then her decision, then her putting it into practice in a lasting and efficient way. For this purpose, we propose a model we have developed during several years in CERES (University of Liège) as well as in DPSS (University of Paris 13), named “Factors of production and perseveration in actions”. If these factors are designated by the first letters of their names, at the heard of the model stands the acronym ASCID (Attitudes, Skills, Cognition, Identity, Decision). Objectives: This model, conceived for health and environment education is not limited to therapeutic patient education, but it fits it very well. The interest and the fecundity of this model have been put to test during more than 25 years with cohorts of students and professionals involved in TPE to analyze situations, cases, and to conceive relevant course of action for the educator and the patient. Description: Methods of diagnostic and of action in TPE superimposed themselves to the model of patient functioning. To help readers assimilate this complex model, we start with a familiar case (AIDS) and we will use frequently cases to illustrate theoretical concepts. [less ▲]Detailed reference viewed: 944 (81 ULg) Social Enterprise in Europe: At the Crossroads of Market, Public Policies and Third SectorDefourny, Jacques ; Nyssens, Marthein Policy and Society (2010), 29(3), 231-232Detailed reference viewed: 260 (7 ULg) Le medicament du mois. Ulipristal acetate: une contraception d'urgence etendue a 5 jours par progesterone receptor modulator (Ellaone).Gaspard, Ulysse ; Kridelka, Frédéric in Revue Médicale de Liège (2010), 65(12), 700-5Emergency contraception is a second chance for prevention of pregnancy after unprotected intercourse. Hormonal emergency contraception with levonorgestrel 1.5 mg, only provides an effective contraception ... [more ▼]Emergency contraception is a second chance for prevention of pregnancy after unprotected intercourse. Hormonal emergency contraception with levonorgestrel 1.5 mg, only provides an effective contraception from 0 to 72 hours after intercourse with decreasing effectiveness as time elapses. It was accordingly mandatory to develop an alternative approach with a stable contraceptive efficacy and good tolerance for 5 days, knowing additionally that the estimated lifespan of sperm in the female genital tract is about 5 days. In comparative studies bearing on more than 3000 young women, the progesterone receptor modulator (PRM) ulipristal acetate, a progesterone antagonist (taken in a single dose of 30 mg), or levonorgestrel (1.5 mg) were administered. Results indicated that the PRM was as effective as levonorgestrel, or even more, kept a stable efficacy for 120 hours after an unprotected intercourse, and was well tolerated. This establishes ulipristal acetate as the new standard for hormonal emergency contraception. [less ▲]Detailed reference viewed: 55 (3 ULg) Le médicament du mois. Nouvelle contraception orale combinée au valerate d'estradiol et au dienogest (Qlaira).Gaspard, Ulysse ; PINTIAUX, Axelle ; Kridelka, Frédéric in Revue Médicale de Liège (2010), 65(12), 706-13In combined oral contraception (OC), a drastic reduction of both ethinylestradiol and androgenic progestins mostly derived from 19 NOR testosterone, allowed to moderately reduce the adverse impact of ... [more ▼]In combined oral contraception (OC), a drastic reduction of both ethinylestradiol and androgenic progestins mostly derived from 19 NOR testosterone, allowed to moderately reduce the adverse impact of classical combined pills on metabolism and circulation (both arterial and venous). However, the marked hepatic action of ethinylestradiol, even in small dosages, lessens the expected risk reduction. For the first time, an OC has been developed, which contains estradiol valerate (with reduced hepatic action because of lack of a 17alpha ethinyl group) with dienogest, a 19 NOR testosterone-derived nonandrogenic progestin, which powerfully inhibits endometrial proliferation. Thanks to a dynamic modulation of estrogen and progestin doses (26 active days + 2 placebo days), an adequate contraceptive effectiveness, a good cycle control and drug tolerance are achieved, similar to those obtained with a classical low-dose OC. Recent data indicate that this new combination reduces the usually observed metabolic impact. An adequate cycle control (with 20% amenorrhea) is achieved for the first time with estradiol valerate + progestin,, in opposition with prior catastrophic results with other formulations containing 17beta-estradiol. A second combination containing estradiol + nomegestrol acetate (monophasic, 24 active days + 4 placebo days) is under study and seems also to yield promising results. Of course, in-depth study of metabolic and vascular effects of these new combinations is mandatory - and ongoing. [less ▲]Detailed reference viewed: 61 (0 ULg) La sociología jurídica en FranciaGarcía Villegas, Mauricio; Lejeune, Aude in García Villegas, Mauricio (Ed.) Sociología y crítica del derecho (2010)Critical review of the French socio-legal studiesDetailed reference viewed: 113 (4 ULg) Diagenèse osseuse et genèse de nodules phosphatés, associés aux sédiments fluvio-lacustres de sites à hominidés miocène (Kenya)DERICQUEBOURG, P.; PERSON, A.; SEGALEN, L. et alPoster (2010)Detailed reference viewed: 48 (12 ULg) Neuregulin-1 modulates the differentiation of neural stem cells in vitro trough an interaction with the Swi/Snf complex.Pirotte, Dorothée ; Wislet, Sabine ; cloes, J. M. et alin Molecular and Cellular Neuroscience (2010)The neuregulin-1 (Nrg-1) gene is translated into several protein isoforms, which are either secreted or membrane-anchored. In vitro, neural stem cells (NSC) express mainly the cystein-rich-domain NRG (CRD ... [more ▼]The neuregulin-1 (Nrg-1) gene is translated into several protein isoforms, which are either secreted or membrane-anchored. In vitro, neural stem cells (NSC) express mainly the cystein-rich-domain NRG (CRD-NRG) isoform, a membrane-anchored type III form. This isoform exhibits a cystein-rich-domain, which constitutes a second transmembrane domain and can be cleaved to release both a signaling EGF-containing domain (ECD) at the cell surface and an intracellular domain (ICD). The main goal of this paper was to determine the exact role of ECD and ICD in NSC survival and differentiation. Using an siRNA approach, we demonstrated that CRD-NRG inhibition was followed by a decrease in NSC proliferation and of neuronal or oligodendroglial differentiation. Overexpression of ICD but not ECD was followed by a decrease in NSC proliferation and an increase in neuronal and oligodendroglial differentiation. Moreover, we showed that ICD physically interacted in cultured NSC with BRM and BAF57, two members of the Swi/Snf remodeling complex, and that ICD stimulation of neuronal cell differentiation is dependent on the presence of BAF57. [less ▲]Detailed reference viewed: 150 (10 ULg)