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See detailL'utilisation du ratio sFlt-1/PlGF dans la prééclampsie: une analyse rétrospective monocentrique
Verbeurgt, Lievine ULg; CHANTRAINE, Frédéric ULg; DE MARCHIN, Jérôme et al

in Revue Médicale de Liège (in press)

La fms-like tyrosine kinase 1 soluble (sFlt-1) est un facteur anti-angiogénique libéré en quantité excessive dans la prééclampsie (PE) et impliqué dans la dysfonction endothéliale. Il est comparé au ... [more ▼]

La fms-like tyrosine kinase 1 soluble (sFlt-1) est un facteur anti-angiogénique libéré en quantité excessive dans la prééclampsie (PE) et impliqué dans la dysfonction endothéliale. Il est comparé au facteur de croissance placentaire pro-angiogénique (PlGF) qui diminue dans la PE. Le ratio sFlt-1/PlGF est présenté dans la littérature comme outil dans la prédiction de la prééclampsie. Un ratio < 38 confirme l’absence de prééclampsie à court-terme. Un ratio ≥ 85 dans la PE précoce (avant 34 semaines aménorrhée (SA)) et ≥ 110 dans le «late onset» (> 34 semaines d’aménorhhée) peut poser le diagnostic de prééclampsie. Dans cette étude rétrospective monocentrique, le ratio sFlt-1/PlGF a été dosé chez 183 patientes à risque dont 67 ont présenté une prééclampsie. Le ratio sFlt-1/PlGF médian pour toutes les patientes évaluées est 100,3. Le ratio médian pour les patientes ayant déclaré une prééclampsie (N=67) est 212,7 alors que celui des femmes sans prééclampsie (N=116) est de 35,4. En accord avec ces analyses, un ratio sFlt-1/PlGF ≥ 38 possède une sensibilité égale à 95,5% et une spécificité égale à 73,3%. Les valeurs prédictives positive (VPP) et négative (VPN) sont, respectivement, 67,4% et 96,6%. Ces résultats suggèrent que le ratio sFlt-1/PlGF peut être une aide dans le diagnostic de la prééclampsie [less ▲]

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See detailLa bataille de l'éclipse (28 mai 585 ACN)
Leloux, Kevin ULg

in Actes du Dixième congrès de l'Association des Cercles francophones d'Histoire et d'Archéologie de Belgique (in press)

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See detailPure and Impure Ancestors at Selinous: a note on Greek theology
Pirenne-Delforge, Vinciane ULg

in Bielawski, Krzysztof (Ed.) Animal Sacrifice in Ancient Greece. Proceedings of the First International Workshop in Kraków (12-14.11.2015) (in press)

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See detailBridging novelty and familiarity-based recognition memory: a matter of timing
Delhaye, Emma ULg; Bastin, Christine ULg; Moulin, Christopher et al

in Visual Cognition (in press)

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See detailTemporality
Cormann, Grégory ULg

in Eshleman, Matthew; Mui, Connie; Perrin, Christophe (Eds.) Sartrean Mind (in press)

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See detailInterpolation schemes for geometrically exact beams: A motion approach
Sonneville, Valentin; Bruls, Olivier ULg; Bauchau, Olivier A.

in International Journal for Numerical Methods in Engineering (in press)

This paper focuses on the interpolation of the kinematic fields describing the configuration of geometrically exact beams, namely, the position and rotation fields. Two kinematic representations are ... [more ▼]

This paper focuses on the interpolation of the kinematic fields describing the configuration of geometrically exact beams, namely, the position and rotation fields. Two kinematic representations are investigated: the classical approach that treats the displacement and rotation fields separately and the motion approach that treats those two fields as a unit. The latter approach is found to be more consistent with the kinematic description of beams. Then, two finite element interpolation strategies are presented and contrasted. The first interpolates the displacement and rotation fields separately, whereas the second interpolates both fields as a unit, in a manner consistent with the motion approach. The performance of both strategies is evaluated in light of the fundamental requirements for the convergence of the finite element method: the ability to represent rigid-body motions and constant strain states. It is shown that the traditional uncoupled interpolation scheme for the position field approximates that based on the motion approach and that the coupling induced by the interpolation of motion yields superior convergence rates for the representation of constant strain states. This property is known to lead to finite elements that are less prone to the locking phenomenon. [less ▲]

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See detailPulse-Based Control Using Koopman Operator Under Parametric Uncertainty
Sootla, Aivar; Ernst, Damien ULg

in IEEE Transactions on Automatic Control (in press)

In applications, such as biomedicine and systems/synthetic biology, technical limitations in actuation complicate implementation of time-varying control signals. In order to alleviate some of these ... [more ▼]

In applications, such as biomedicine and systems/synthetic biology, technical limitations in actuation complicate implementation of time-varying control signals. In order to alleviate some of these limitations, it may be desirable to derive simple control policies, such as step functions with fixed magnitude and length (or temporal pulses). In this technical note, we further develop a recently proposed pulse-based solution to the convergence problem, i.e., minimizing the convergence time to the target exponentially stable equilibrium, for monotone systems. In particular, we extend this solution to monotone systems with parametric uncertainty. Our solutions also provide worst-case estimates on convergence times. Furthermore, we indicate how our tools can be used for a class of non-monotone systems, and more importantly how these tools can be extended to other control problems. We illustrate our approach on switching under parametric uncertainty and regulation around a saddle point problems in a genetic toggle switch system. [less ▲]

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See detailReliability of unipodal and bipodal counter movement jump landings in a recreational male population
Schwartz, Cédric ULg; Forthomme, Bénédicte ULg; Paulus, Julien ULg et al

in European Journal of Sport Science (in press)

Movement patterns during landing have been suggested to be related to injury risk. The purpose of this study was to determine the inter-session reliability of kinematic variables and ground reaction ... [more ▼]

Movement patterns during landing have been suggested to be related to injury risk. The purpose of this study was to determine the inter-session reliability of kinematic variables and ground reaction forces during landing in a population of male recreational athletes after a counter movement jump. Both unipodal and bipodal landings were evaluated. Furthermore, the possibility to improve landing reliability with a verbal instruction was also studied. Twenty- four male volunteers with no history of lower-extremity trauma were randomly assigned to two groups (with and without verbal landing instruction). An optoelectronic 3D system and force plates were used to measure the lower-limb joint angles and the ground reaction forces during landing. Intraclass correlation values show moderate to excellent inter-session reliability for the bipodal task (ICC average: 0.80, range: 0.46 to 0.97) and poor to excellent reliability for the unipodal task (ICC average: >0.75, range: 0.20 to 0.95). However, large standard errors of measurement values at the ankle joint at impact (27.6 ± 11.5°) and for the vertical ground reaction forces (394 ± 1091 N) show that some variables may not be usable in practice. The verbal instruction had a negative effect on the reliability of unipodal landing but improved the reliability of bipodal landing. These findings show that the reliability of a landing task is influenced by its motor complexity as well as the instruction given to the subject. [less ▲]

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See detailMultiple Gas-Phase Conformations of a Synthetic Linear Poly(acrylamide) Polymer Observed Using Ion Mobility-Mass Spectrometry
Haler, Jean ULg; Far, Johann ULg; Aqil, Abdelhafid ULg et al

in Journal of the American Society for Mass Spectrometry (in press)

Ion mobility-mass spectrometry (IM-MS) has emerged as a powerful separation and identification tool to characterize synthetic polymer mixtures and topologies (linear, cyclic, star-shaped ... [more ▼]

Ion mobility-mass spectrometry (IM-MS) has emerged as a powerful separation and identification tool to characterize synthetic polymer mixtures and topologies (linear, cyclic, star-shaped,...). Electrospray coupled to IM-MS already revealed the coexistence of several charge state-dependent conformations for a single charge state of biomolecules with strong intramolecular interactions, even when limited resolving power IM-MS instruments were used. For synthetic polymers, the sample's polydispersity allows the observation of several chain lengths. A unique collision cross-section (CCS) trend is usually observed when increasing the degree of polymerization (DP) at constant charge state, allowing the deciphering of different polymer topologies. In this paper, we report multiple coexisting CCS trends when increasing the DP at constant charge state for linear poly(acrylamide) PAAm in the gas phase. This is similar to observations on peptides and proteins. Biomolecules show in addition population changes when collisionally heating the ions. In the case of synthetic PAAm, fragmentation occurred before reaching the energy for conformation conversion. These observations, which were made on two different IM-MS instruments (SYNAPT G2 HDMS and high resolution multi-pass cyclic T-Wave prototype from Waters), limit the use of ion mobility for synthetic polymer topology interpretations to polymers where unique CCS values are observed for each DP at constant charge state. [less ▲]

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See detailA biased random key genetic algorithm applied to the electric distribution network reconfiguration problem
de Faria Jr., Haroldo; Resende, Mauricio; Ernst, Damien ULg

in Journal of Heuristics (in press)

This work presents a biased random-key genetic algorithm (BRKGA) to solve the electric distribution network reconfiguration problem (DNR). The DNR is one of the most studied combinatorial optimization ... [more ▼]

This work presents a biased random-key genetic algorithm (BRKGA) to solve the electric distribution network reconfiguration problem (DNR). The DNR is one of the most studied combinatorial optimization problems in power system analysis. Given a set of switches of an electric network that can be opened or closed, the objective is to select the best configuration of the switches to optimize a given network objective while at the same time satisfying a set of operational constraints. The good performance of BRKGAs on many combinatorial optimization problems and the fact that it has never been applied to solve DNR problems are the main motivation for this research. A BRKGA is a variant of random-key genetic algorithms, where one of the parents used for mating is biased to be of higher fitness than the other parent. Solutions are encoded by using random keys, which are represented as vectors of real numbers in the interval (0,1), thus enabling an indirect search of the solution inside a proprietary search space. The genetic operators do not need to be modified to generate only feasible solutions, which is an exclusive task of the decoder of the problem. Tests were performed on standard distribution systems used in DNR studies found in the technical literature and the performance and robustness of the BRKGA were compared with other GA implementations. [less ▲]

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See detailA damage to crack transition model accounting for stress triaxiality formulated in a hybrid non-local implicit discontinuous Galerkin - cohesive band model framework
Leclerc, Julien ULg; Wu, Ling ULg; Nguyen, Van Dung ULg et al

in International Journal for Numerical Methods in Engineering (in press)

Modelling the entire ductile fracture process remains a challenge. On the one hand, continuous damage models succeed in capturing the initial diffuse damage stage but are not able to represent ... [more ▼]

Modelling the entire ductile fracture process remains a challenge. On the one hand, continuous damage models succeed in capturing the initial diffuse damage stage but are not able to represent discontinuities or cracks. On the other hand, discontinuous methods, as the cohesive zones, which model the crack propagation behaviour, are suited to represent the localised damaging process. However, they are unable to represent diffuse damage. Moreover, most of the cohesive models do not capture triaxiality effect. In this paper, the advantages of the two approaches are combined in a single damage to crack transition framework. In a small deformation setting, a non-local elastic damage model is associated with a cohesive model in a discontinuous Galerkin finite element framework. A cohesive band model is used to naturally introduce a triaxiality-dependent behaviour inside the cohesive law. Practically, a numerical thickness is introduced to recover a 3D-state, mandatory to incorporate the in-plane stretch effects. This thickness is evaluated to ensure the energy consistency of the method and is not a new numerical parameter. The traction-separation law is then built from the underlying damage model. [less ▲]

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See detailPrévalence et risque de maltraitance des aînés à domicile en Wallonie : retour sur un dispositif d’enquête
Nisen, Laurent ULg

in "Vieillir aujourd'hui des mo(n)des recomposés" (in press)

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See detailDe automatische toekenning van rechten in de Belgische sociale bescherming. Stand van zaken en opties voor de toekomst
Buysse, Linde; Goedemé, Tim; Janssens, Julie et al

in Pauvreté en Belgique. Annuaire 2017 (in press)

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See detailSartre and Merleau-Ponty
Caeymaex, Florence ULg; Cormann, Grégory ULg

in Eshleman, Matthew; Mui, Connie; Perrin, Christophe (Eds.) Sartrean Mind (in press)

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See detailClinical classification criteria for radicular pain caused by lumbar disc herniation: the RAPIDH criteria (RAdicular PaIn caused by Disc Herniation)
Genevay, Stéphane; Courvoisier, Delphine; Konstantinou, Kika et al

in Spine Journal (in press)

BACKGROUND CONTEXT: Classification criteria are recommended for diseases that lack specific biomarkers to improve homogeneity in clinical research studies. Because imaging evidence of lumbar disc ... [more ▼]

BACKGROUND CONTEXT: Classification criteria are recommended for diseases that lack specific biomarkers to improve homogeneity in clinical research studies. Because imaging evidence of lumbar disc herniations (LDHs) may not be associated with symptoms, clinical classification criteria based on patient symptoms and physical examination findings are required. PURPOSE: This study aimed to produce clinical classification criteria to identify patients with radicular pain caused by LDH. STUDY DESIGN: The study design was a two-stage process. Phase 1 included a Delphi process and Phase 2 included a cohort study. PATIENT SAMPLE: The patient sample included outpatients recruited from spine clinics in five countries. OUTCOME MEASURES: The outcome measures were items from history and physical examination. MATERIALS AND METHODS: In Phase 1, 17 spine experts participated in a Delphi process to select symptoms and signs suggesting radicular pain caused by LDH. In Phase 2, 19 different clinical experts identified patients they confidently classified as presenting with (1) radicular pain caused by LDH, (2) neurogenic claudication (NC) caused by lumbar spinal stenosis, or (3) non-specific low back pain (NSLBP) with referred leg pain. Patients completed survey items and specialists documented examination signs. A score to predict radicular pain caused by LDH was developed based on the coefficients of the multivariate model. An unrestricted grant of less than US$15,000 was received from MSD: It was used to support the conception of the Delphi, data management, and statistical analysis. No fees were allocated to participating spine specialists. RESULTS: Phase 1 generated a final list of 74 potential symptoms and signs. In Phase 2, 209 patients with pain caused by LDH (89), NC (63), or NSLBP (57) were included. Items predicting radicular pain caused by LDH (p<.05) were monoradicular leg pain distribution, patient-reported unilateral leg pain, positive straight leg raise test <60° (or femoral stretch test), unilateral motor weakness, and asymmetric ankle reflex. The score had an AUC of 0.91. An easy-to-use weighted set of criteria with similar psychometric characteristics is proposed (specificity 90.4%, sensitivity 70.6%). CONCLUSIONS: Classification criteria for identifying patients with radicular pain caused by LDH are proposed. Their use could improve the homogeneity of patients enrolled in clinical research studies. [less ▲]

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See detailStructural Basis for Plant Plasma Membrane Protein Dynamics and Organization into Functional Nanodomains
Gronnier; Crowet, Jean-Marc ULg; Habenstein, Birgit et al

in eLife (in press)

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See detailExperimental and theoretical analysis of shear bolted connections for tubular structures
D'Antimo, Marina ULg; Demonceau, Jean-François ULg; Jaspart, Jean-Pierre ULg et al

in Journal of Constructional Steel Research (in press)

In this paper, numerical and experimental investigations devoted to the evaluation of the bearing resistance of tubular members with gusset plates and through-all long bolts are presented. Unlike lap ... [more ▼]

In this paper, numerical and experimental investigations devoted to the evaluation of the bearing resistance of tubular members with gusset plates and through-all long bolts are presented. Unlike lap shear joints, the analysed connection evidences a reduced confinement of the bearing area associated to the use of long bolts and the presence of a gap in the member, which can lead, consequently, to a reduction of the bearing resistance. In order to investigate the behaviour of shear connections made up of thin and thick SHS (Square Hollow Section) profiles and long bolts, an experimental test campaign including 24 specimens and FE simulations have been conducted. Both experimental and FE results have confirmed the influence of local instability on the hole in bearing resistance of thin profiles and the poor accuracy of the available standards for this particular joint typology. In particular, the performed comparisons have shown that, for thin profiles, EC3 model is likely to overestimate the resistance, while for higher thickness of the SHS conservative predictions are obtained. The present paper presents the conducted experimental and numerical investigations, highlighting at the end the need for a proper formulation able to account for the local instability effect on the bearing resistance. [less ▲]

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See detailAmerican Literature and the Toxic Sublime
Lombard, David ULg

Book published by Quodlibet (2018)

According to Jennifer A. Peeples, the “toxic sublime” refers to “the tensions that arise from recognizing the toxicity of a place, object or situation, while simultaneously appreciating its mystery ... [more ▼]

According to Jennifer A. Peeples, the “toxic sublime” refers to “the tensions that arise from recognizing the toxicity of a place, object or situation, while simultaneously appreciating its mystery, magnificence and ability to inspire awe”. As an alternative to the “technological sublime”, which creates awe through the contemplation of human efforts to master the environment, it urges us to consider the negative and noxious aspects of such endeavours. Through her analysis of Edward Burtynsky’s “Manufactured Landscapes”, Peeples introduces a new form of sublime aesthetics, which may also be used as a valuable trope in the study of the relationship between literature and our physical environment. My goal in this study is to extend such considerations to the recent history of American literature, using examples such as Rachel Carson’s “A Fable for Tomorrow” (1962), which describes the invisible “lethal film” made of “systemic insecticides” that converts natural species into carcinogenic poison, thus depicting landscapes as intoxicated “places of beauty” that no longer symbolise human abilities to dominate the environment but rather their lack of control over it. Likewise, in Don DeLillo’s novel White Noise (1985), the protagonist Jack Gladney experiences his daughter’s “utterance” of the car brand “Toyota Celica” as “beautiful and mysterious”, which “str[ikes] [him] with the impact of a moment of splendid transcendence”. Gladney then proceeds to relate his family’s “garbage” to his relatives’ selves as it is a “sign[] of [their] deepest nature”. Jack’s approach to human waste shows that what Cynthia Deitering defines as the “toxic consciousness”—the general awareness of the existence of toxicity in the landscape—is to be associated with the protagonist’s idea of “consumer consciousness”. Indeed, the term toxicity can also metaphorically refer to the “poisoned” nature of our relationship to and perception of specific places, objects, or situations. The viewer in national parks, for instance, tends to see the “sublime landscape” as a “series of picturesque scenes”, which allows him to consume the scene as an “object of artistic consumption”. Such examples point to different but related ways of examining distinct forms of toxicity that characterise our relationship with our physical environment. They also prompt us to examine the problematic nature of technology and progress while dealing with the elusive and paradoxical nature of the technological sublime. [less ▲]

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See detailAn Optimal Control Formulation of Pulse-Based Control Using Koopman Operator
Sootla, Aivar; Mauroy, Alexandre; Ernst, Damien ULg

E-print/Working paper (2018)

In many applications, and in systems/synthetic biology in particular, it is desirable to compute control policies that force the trajectory of a bistable system from one equilibrium (the initial point) to ... [more ▼]

In many applications, and in systems/synthetic biology in particular, it is desirable to compute control policies that force the trajectory of a bistable system from one equilibrium (the initial point) to another equilibrium (the target point), or in other words to solve the switching problem. It was recently shown that, for monotone bistable systems, this problem admits easyto-implement open-loop solutions in terms of temporal pulses (i.e., step functions of fixed length and fixed magnitude). In this paper, we develop this idea further and formulate a problem of convergence to an equilibrium from an arbitrary initial point. We show that this problem can be solved using a static optimization problem in the case of monotone systems. Changing the initial point to an arbitrary state allows to build closed-loop, event-based or open-loop policies for the switching/convergence problems. In our derivations we exploit the Koopman operator, which offers a linear infinite-dimensional representation of an autonomous nonlinear system. One of the main advantages of using the Koopman operator is the powerful computational tools developed for this framework. Besides the presence of numerical solutions, the switching/convergence problem can also serve as a building block for solving more complicated control problems and can potentially be applied to non-monotone systems. We illustrate this argument on the problem of synchronizing cardiac cells by defibrillation. Potentially, our approach can be extended to problems with different parametrizations of control signals since the only fundamental limitation is the finite time application of the control signal. [less ▲]

Detailed reference viewed: 23 (3 ULg)