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See detailComportements à risques et maladies cardio-vasculaires, comment infléchir le cours des choses?
Krzesinski, Jean-Marie ULg; andre, Jean-François

Conference (2014, April 01)

Entre recommandations, croyances et attitudes des médecins, croyances, attitudes et vécu des patients, comment améliorer la prévention dans le domaine cardio-vasculaire?

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See detailIntegration of near-surface geophysical, geological and hydrogeological data with multiple-point geostatistics in alluvial aquifers
Hermans, Thomas ULg

Doctoral thesis (2014)

Alluvial plains constitute essential geological bodies for environmental studies such as contaminated sites remediation, low-enthalpy geothermal energy or groundwater resources. The heterogeneity of these ... [more ▼]

Alluvial plains constitute essential geological bodies for environmental studies such as contaminated sites remediation, low-enthalpy geothermal energy or groundwater resources. The heterogeneity of these deposits governs flow processes and needs to be quantified. A proper description of such complex deposits requires an integrated approach combining geological, geophysical and hydrogeological data. Solving such spatial inverse problems in the Earth Sciences remains a considerable challenge given the large number of parameters to invert for, the non-linearity of forward models and, as a result, the ill-posedness of the problem. Geostatistics is therefore needed to specify prior models, more particularly, information to control the spatial features of the inverse solutions. Two-point geostatistical approaches have been developed to describe the heterogeneity of one geological formation but fail to reproduce the heterogeneity of fluvial deposits with multiple facies. Multiple-point statistics (MPS) introduced the training image (TI) concept to replace the variogram within an extended sequential simulation framework. The use of geophysics to constrain such simulations has been studied in the petroleum industry with wave-based methods (seismic reflection), but little research has been done to assess the use of near-surface potential methods to condition MPS in environmental studies. In this work, we propose to integrate geological (borehole logs), geophysical (electrical resistivity tomography (ERT) profiles) and hydrogeological (hydraulic heads) data within MPS models on the alluvial plain of the Meuse River, Belgium. Potential-based geophysical methods being integrative, they suffer from a relatively poor resolution. We first study how we can improve the informative content of geophysical inversion by including prior information in the ERT inverse problem. Three methods are tested and compared in several field cases, namely the reference model inversion, the structural inversion and the regularized geostatistical inversion. If every method has advantages and drawbacks, the best suited method for the considered problem is the regularized geostatistical method. Electromagnetic borehole logs enable to derive the vertical correlation length of electrical resistivity in the deposits and to subsequently use it to constrain the inversion. In addition to the knowledge of the bedrock position, it enables to retrieve an electrical resistivity distribution of the deposits close to direct observations. This ensures that geophysical models will be informative to constrain MPS simulations. Given the lack of geological and sedimentological data to build accurate TIs, a data base of TIs is built using several different parameters and scenarios. They are all based on a three facies description: clay/loam, sand and gravel corresponding to low, intermediate and high hydraulic conductivity. Then, we develop a methodology to verify the consistency of independently-built TIs with geophysical data. Our methodology starts by creating subsurface models with each TI. From these models we create synthetic geophysical data and from this synthetic data, synthetic inverted models. These models are now compared with a single inverted model obtained from the field survey, allowing for our definition of what is ``consistent''. To that extent, we calculate the Euclidean distance between any two inverted models as well as field data and visualize the results in a 2D or 3D space using multidimensional scaling (MDS). With this technique, it is possible to verify if field cases fall in the distribution represented by synthetic cases, and thus are consistent with them. In a second step, we present a cluster analysis on the MDS-map to highlight which parameters are the most sensitive for the construction of TI. Based on this analysis, a probability of each geological scenario is computed through kernel smoothing of the densities in reduced projected metric space. The integration of hydrogeological data is made through a stochastic inversion method: the probability perturbation method (PPM), using MPS constrained with geophysical data to generate models. The PPM algorithm automatically seeks solutions fitting both hydrogeological data and training-image based geostatistical constraints. Only geometrical features of the model are affected by the perturbation, i.e. we do not attempt to directly find the optimal value of hydrogeological parameters (chosen a priori), but the optimal spatial distribution of facies whose prior distribution is quantified in a training image. Tracing experiments may be used to further constrain hydrogeological models. ERT has proven its ability to monitor salt tracer tests, but few studies have investigated its performances in thermal tracing experiments. In this study, we demonstrate the ability of surface and crosshole ERT to image quantitatively temperature changes during heat injection experiments. Such resistivity data provides important information to improve hydrogeological models. Our study proves that ERT, especially crosshole ERT, is a reliable tool to follow thermal tracing experiments. It also confirms that ERT should be included to in situ techniques to characterize heat transfer in the subsurface and to monitor geothermal resources exploitation. [less ▲]

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See detailNeuropathies proximales du membre supérieur
WANG, François-Charles ULg

Conference (2014, April 01)

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See detailEpoch-dependent absorption line profile variability in lambda Cep
Uuh-Sonda, J. M.; Rauw, Grégor ULg; Eenens, P. et al

in Revista Mexicana de Astronomia y Astrofisica (2014), 50

We present the analysis of a multi-epoch spectroscopic monitoring campaign of the O6 Ief star lambda Cep. Previous observations reported the existence of two modes of non-radial pulsations in this star ... [more ▼]

We present the analysis of a multi-epoch spectroscopic monitoring campaign of the O6 Ief star lambda Cep. Previous observations reported the existence of two modes of non-radial pulsations in this star. Our data reveal a much more complex situation. The frequency content of the power spectrum considerably changes from one epoch to the other. We find no stable frequency that can unambiguously be attributed to pulsations. The epoch-dependence of the frequencies and variability patterns are similar to what is seen in the wind emission lines of this and other Oef stars, suggesting that both phenomena likely have the same, currently still unknown, origin. [less ▲]

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See detailEccentric training for elbow hypermobility
Kaux, Jean-François ULg; Delvaux, François ULg; Forthomme, Bénédicte ULg et al

in British Journal of Sports Medicine (2014, April), 48(7), 154

Background: Patients with hypermobility suffer from joints problems and chronic pain is the most frequently reported symptom. Objective: Eccentric muscle strengthening could be very important to protect ... [more ▼]

Background: Patients with hypermobility suffer from joints problems and chronic pain is the most frequently reported symptom. Objective: Eccentric muscle strengthening could be very important to protect hypermobile joints. Design: Case report. Patient: A girl (16 y.o.) affected by an Ehler-Danlos syndrome presented pain in the right elbow and the right wrist after a season of tennis. Interventions: Her training consisted of wrist prono-supination and flexion-extension muscle group reinforcement and proprioceptive training. To protect the wrist against excessive load, the eccentric strengthening exercises of prono-supinator and flexor-extensor muscles of elbow and wrist were undertaken gradually, at increasing speeds within a limited range of motion in flexion and extension, on an isokinetic device after an evaluation. She was also given an orthesis restricting the joint range of motion of the wrist. Main outcome measurements: The evaluation was made by isokinetic evaluation, visual analog scale and MOS-SF36 questionnaire before and after training. Results: The patient rapidly noted a decrease in pain and an increase in the stability of her right arm even when playing tennis. Isokinetic evaluation objectified a significant improvement in maximal torque in flexion-extension muscles of the right elbow. She was also given individualized home exercises. Conclusions: The goal of this eccentric training is to avoid hypermobility by using the muscles as a protective brake in the control of joint positioning. Muscles can be reinforced in eccentric mode with starting position at the maximum length of these muscles when unstreched. The exercises can be carried out safely on an isokinetic device, at slow speed and limited range of joint motion to avoid risk of luxation. Thus, in this case report, the eccentric exercises using an isokinetic device were effective to safely reinforce the muscles as a protective brake for joint hypermobility and prevent pain during practicing tennis. [less ▲]

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See detailProduction de l'habitat et enjeux territoriaux
Dethier, Perrine ULg; Halleux, Jean-Marie ULg

Report (2014)

Le projet de recherche est basé sur le concept de système de production de l'habitat. Un système de production de l'habitat vise à accroître et à améliorer l'offre en logements. Il se structure par les ... [more ▼]

Le projet de recherche est basé sur le concept de système de production de l'habitat. Un système de production de l'habitat vise à accroître et à améliorer l'offre en logements. Il se structure par les interactions entre les modes d'habiter (la demande), les modes de production (l'offre) et les modes de gestion (l'intervention de la puissance publique). Pour le contexte wallon, le système de production actuel est lié à un usage peu parcimonieux de la ressource foncière et à des problèmes importants d’étalement de la périurbanisation. Néanmoins, des signaux avant-coureurs de la mise en place d'un système de production plus vertueux vis-à-vis des principes stratégiques de l'aménagement du territoire semblent se manifester. La recherche I.5. intitulée « Production de l’habitat et enjeux territoriaux » ambitionne d'étudier l'ampleur de ces changements et de comprendre quels sont les processus socioéconomiques qui les instituent. Au final, son objectif est de préciser comment l’intervention de la puissance publique peut s’appuyer sur ces pratiques émergentes en vue de soutenir la transition vers un nouveau système pour la production de l’habitat wallon. Notre ambition est donc d’identifier les conditions qui conduisent à des pratiques plus vertueuses vis-à-vis des principes stratégiques de l’aménagement durable, afin de les renforcer et de les généraliser dès que possible. [less ▲]

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See detailA new methodological approach for error distributions selection in Finance
Hambuckers, julien ULg; Heuchenne, Cédric ULg

Conference (2014, April)

In this article, we propose a robust methodology to select the most appropriate error distribution candidate, in a classical multiplicative heteroscedastic model. In a first step, unlike to the ... [more ▼]

In this article, we propose a robust methodology to select the most appropriate error distribution candidate, in a classical multiplicative heteroscedastic model. In a first step, unlike to the traditional approach, we don't use any GARCH-type estimation of the conditional variance. Instead, we propose to use a recently developed nonparametric procedure (Mercurio and Spokoiny, 2004): the Local Adaptive Volatility Estimation (LAVE). The motivation for using this method is to avoid a possible model misspecification for the conditional variance. In a second step, we suggest a set of estimation and model selection procedures (Berk-Jones tests, kernel density-based selection, censored likelihood score, coverage probability) based on the so-obtained residuals. These methods enable to assess the global fit of a given distribution as well as to focus on its behavior in the tails. Finally, we illustrate our methodology on three time series (UBS stock returns, BOVESPA returns and EUR/USD exchange rates). [less ▲]

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See detailDynamics of a Strongly Nonlinear Spacecraft Structure Part I: Experimental Identification
Noël, Jean-Philippe ULg; Renson, Ludovic ULg; Kerschen, Gaëtan ULg

in Proceedings of the 13th European Conference on Spacecraft Structures, Materials and Environmental Testing (2014, April)

The present paper addresses the identification of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. The complete identification procedure, from ... [more ▼]

The present paper addresses the identification of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. The complete identification procedure, from nonlinearity detection and characterization to parameter estimation, is carried out based upon experimental sine-sweep data collected during a classical spacecraft qualification campaign. [less ▲]

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See detailDynamics of a Strongly Nonlinear Spacecraft Structure Part II: Modal Analysis
Renson, Ludovic ULg; Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg

in Proceedings of the 13th European Conference on Spacecraft Structures, Materials & Environmental Testing (2014, April)

The present paper investigates the dynamics of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. A full-scale finite element model is built for ... [more ▼]

The present paper investigates the dynamics of a real-life spacecraft structure possessing a strongly nonlinear component with multiple mechanical stops. A full-scale finite element model is built for gaining additional insight into the nonlinear dynamics that was observed experimentally in a companion paper (Part I). To this end, advanced techniques and theoretical concepts such as numerical continuation and nonlinear normal modes are exploited. [less ▲]

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See detailThe Neural Correlates of Re-cancellation Behaviors in Unilateral Neglect: A Neuropsychological Approach
Wansard, Murielle ULg; Bastin, Christine ULg; Meulemans, Thierry ULg

Poster (2014, April)

The present study focused on re-cancellation behaviors in unilateral neglect (i.e., the tendency to search repeatedly items located on the right side in visual search tasks), and used a neuropsychological ... [more ▼]

The present study focused on re-cancellation behaviors in unilateral neglect (i.e., the tendency to search repeatedly items located on the right side in visual search tasks), and used a neuropsychological approach to identify the cerebral correlates of this deficit. Fourteen patients suffering from left neglect and 14 elderly age-matched controls performed a cancellation task without visual feedback. Neglect patients cancelled fewer targets than controls, and re-cancelled an abnormally high number of targets. Lesion maps were used to compare the location of brain damage in neglect patients with the highest versus the lowest percentage of re-cancellations. Anatomical data revealed that the right insula is commonly damaged in 5 out of 6 patients with the highest re-cancellation percentage, but is spared in the subgroup of patients with the lowest re-cancellation percentage. These results suggest that damage to the right insula may contribute to pathological visual search in spatial neglect, possibly by reducing interaction between the ventral and dorsal attention network (the latter being more directly involved in spatial processes). [less ▲]

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See detailEcomorphology of the vertebral column: preliminary study
Gillet, Amandine; Ninane, Catherine; Zaeytydt, Esther et al

Poster (2014, April)

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See detailCeci n’est pas un conseil !
Choffray, Jean-Marie ULg

E-print/Working paper (2014)

La « Grande Récession de 2008 » a un mérite. Un seul ! Elle a rendu public le fait que personne ne savait exactement ce qui s’était passé, ni ce qui se passait. Pourquoi une telle crise de confiance avait ... [more ▼]

La « Grande Récession de 2008 » a un mérite. Un seul ! Elle a rendu public le fait que personne ne savait exactement ce qui s’était passé, ni ce qui se passait. Pourquoi une telle crise de confiance avait-elle vu le jour ? Quelles en seraient les conséquences ? Toutes et tous se sont trompés, y compris les meilleurs. Même celles et ceux qui étaient convaincus d’avoir raison ! Plus que jamais, l’incertitude, la saine et souveraine incertitude, garantit la liberté de l’investisseur... et du professeur ! [less ▲]

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See detailEsiti funesti della vittoria di Ravenna. La morte e i funerali di Gaston de Foix, duca di Nemours
Dumont, Jonathan ULg; Marchandisse, Alain ULg

in Bolognesi, Dante; Chittolini, Giorgio; Giovannini, Carla (Eds.) et al 1512. La battaglia du Ravenna, l’Italia, l’Europa (2014)

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See detailExamining the Effect of Earnings Management on Bid-Ask Spread and Market Liquidity
Sougné, Danielle ULg; Ajina, Aymen

E-print/Working paper (2014)

The main purpose of this paper is to argue the extent that earnings management lowers liquidity. It should increase information asymmetry and impair trading liquidity. Using a sample of French firms from ... [more ▼]

The main purpose of this paper is to argue the extent that earnings management lowers liquidity. It should increase information asymmetry and impair trading liquidity. Using a sample of French firms from 2008 to 2011, we find that firms that manage earnings have wider bid-ask spreads. Our results are robust for both of two well established measures of market liquidity. Therefore the empirical results indicate that firms that exhibit greater earnings management are associated with lower market liquidity. These findings are in line with adverse selection and shed light on the role corporate governance devices can play in the consideration of shareholder interest’s protection, which leads to improved stock market liquidity levels. [less ▲]

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See detailSTI narratives in Wallonia: A complex interplay
Charlier, Nathan ULg

Conference (2014, April)

It is widely acknowledged that scientific research and science, technology and innovation (STI) policies within the US and the EU have gone through deep changes for about 30 years. Many scholars from ... [more ▼]

It is widely acknowledged that scientific research and science, technology and innovation (STI) policies within the US and the EU have gone through deep changes for about 30 years. Many scholars from science and technology studies and innovation studies have investigated these policy changes, and the publication of “The New Production of Knowledge” (Gibbons et al., 1994) paved the way for vigorous debates on regimes of knowledge production (Hessels & Van Lente, 2008). While different general models were proposed to describe a transition (see, e.g. “mode 2 production of knowledge”, “post normal science”, “strategic science”, “academic capitalism”), these models often posit a dichotomous history, stating that a new regime simply succeeded the previous one (Rip, 2000). In a nutshell, the old regime characterized by strong public intervention and a linear conception of innovation is replaced by a new regime where research and innovation are conceived in systemic terms, regarding their strategic interest for the economy and their societal relevance. This dichotomous conception of STI policy change has been criticized regarding its historical accuracy, e.g. with Pestre (2003), showing that the autonomy of research that characterizes the old regime, or “mode 1” is While the diagnosis of these various science and technology policy studies is not to be dispraised concerning the different effects they emphasize, These macro-perspectives are of little use when it comes to study a local situation they lack acuteness to properly describe and compare empirical observation of such policy changes. This issue is even more salient for empirical work to be conducted in states where multi-level policies are crafted on different, sometimes overlapping national and regional polities. In Belgium, the case in point in my PhD researches, the above-mentioned studies are of little use to characterize the actual state and interplay of Walloon and Flemish STI systems. Hence, there is a need to develop theoretical approaches paying greater attention to local specificities and nuances. My proposal builds on an analysis of STI policies based on coexisting, and sometimes competing “narratives”. In the vein of Stone (1989) and Radaelli (2000), this paper aims at comparing the different policy narratives that circulates as rationale for STI policies in Wallonia, to identify their variants and to study their interplay. Policy narratives give meaning to complex realities, they help making sense of things, but they also contain a plot; they are articulating elements in a logical sequence (with, e.g., causalities, cf. Stone, 1989). As such, they are resources for action: they are descriptive and prescriptive. The broad literature of innovation studies, and its diffusion through the EU or the OECD already provides the Walloon STI stakeholders with different master-narratives (Sum & Jessop, 2013). So far, I could distinguish four different master-narratives in the literature as well as in Walloon stakeholders ‘discourses: • “The Knowledge-based economy” (KBE). KBE seems to be the “dominant” master-narrative today. In a nutshell, this narrative runs as follow (see OECD, 1996): knowledge is the source of economic growth. Since innovation and market success are better encountered through network management and the intertwinement of industry and university, STI institutions must be organized accordingly, in order to achieve a sustained growth and a “better competitiveness” o Variants of this narrative are, e.g. the triple-helix model (Etzkowitz & Leydesdorff, 2000), or National innovation system (Freeman, 1987, Lundvall, 1988). • Grand societal challenges: This recent master-narrative is being promoted by the OECD and the EU (see, e.g., Lund Declaration, 2009). It states that scientific research should benefit of high (public) funding in certain areas, or regarding certain issues. High means for strategic research should help to solve major problems such as climate change, ageing population, energy supply and consumption, cancer, etc. This narrative calls for mission oriented STI policy, so the concern here is not (solely/primarily) economic (Kallerud et al 2013). • “Science, the endless frontier” - continued: famously reported by V. Bush (1945), this master-narrative is still of common use among STI stakeholders. With this narrative, science is considered a public good, the state has to fund it because the linear conception of innovation and serendipity assure technological and economic progress in the end – the rationale is based on economic aspects (the state must fund research because it is a special kind of good and the market efficiency will not work, and basic research is the source of marketable innovation). • “Science for the sake of science”: in this narrative, science is considered as common good regardless of the potential economic impacts (and usefulness to address other societal issues) – we can make a parallel with the idea that artistic creation is worth it: for the beauty, for the critique, science here is considered as a superior activity that brings rationality and knowledge to the society as long as it is independent from “external influences” (Bonneuil & Joly, 2013) – cf. “mertonian Ethos” of Communalism, Universalism, Disinterestedness, Originality and Skepticism. Other examples / variants of this narrative include the idea that science contributes to the greatness of Nation, that science fights obscurantism, and so on and so forth. (examples : peer review, excellence, Copernican revolution are compatible storylines with science for the sake of science : a self-supporting system) While these master-narratives are present in international, academic literature, this paper focuses on their local manifestations. This study compares three critical moments: in different situations, various STI stakeholders (government, researchers, administrative staff, journalists, academic authorities, etc.) publicly expressed their views on the organization and funding of scientific research and innovation activities, and the role of STI within the region. I analyzed the discourses in press articles, policy documents, public statements, allocutions and opinion paper, blogs, etc. I intentionally sampled for heterogeneity since I’m looking for variations and multiple use of narratives. The analysis of the Walloon case permits to overcome the double dichotomy of dominant vs. counter narrative and old vs. new regime. The different narratives, in context, are concurrent but they are not mutually exclusive: while the narratives purport different ideologies, different visions of the role of science and of the state intervention, one is not being erased by the advent of another. Rather, I could find out that narratives “overlap”, and one narrative does not constitute the only resource of a (group of) actors. In situation, the actors use one or multiple narratives, regarding the context, the public, the goal of a policy, etc., in a dynamic of conflict or compromise. This description of the transition is more accurate than the one provided with a sequence of two regimes, since the flexible use of multiple narratives accounts for the continuity of certain institutions (justified by, e.g., a version of “science for the sake of science”) as well as for certain reforms in STI policy (that are inspired by the KBE narrative, for example). [less ▲]

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