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See detailKranzhugeln et seconde révolution urbaine en Haute Mésopotamie au IIIe millénaire av. J.-C.
Mas, Juliette ULg

Scientific conference (2017, April)

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See detailSize fractionation as a tool for separating charcoal of different fuel source and recalcitrance in the wildfire ash layer
Mastrolonardo, Giovanni ULg

in Science of the Total Environment (2017), 595

Charcoal is a heterogeneous material exhibiting a diverse range of properties. This variability represents a serious challenge in studies that use the properties of natural charcoal for reconstructing ... [more ▼]

Charcoal is a heterogeneous material exhibiting a diverse range of properties. This variability represents a serious challenge in studies that use the properties of natural charcoal for reconstructing wildfires history in terrestrial ecosystems. In this study, we tested the hypothesis that particle size is a sufficiently robust indicator for separating forest wildfire combustion products into fractions with distinct properties. For this purpose, we examined two different forest environments affected by contrasting wildfires in terms of severity: an eucalypt forest in Australia, which experienced an extremely severe wildfire, and a Mediterranean pine forest in Italy, which burned to moderate severity. We fractionated the ash/charcoal layers collected on the ground into four size fractions (>2, 2–1, 1–0.5, <0.5 mm) and analysed them for mineral ash content, elemental composition, chemical structure (by IR spectroscopy), fuel source and charcoal reflectance (by reflected-light microscopy), and chemical/thermal recalcitrance (by chemical and thermal oxidation). At both sites, the finest fraction (<0.5 mm) had, by far, the greatest mass. The C concentration and C/N ratio decreased with decreasing size fraction, while pH and the mineral ash content followed the opposite trend. The coarser fractions showed higher contribution of amorphous carbon and stronger recalcitrance. We also observed that certain fuel types were preferentially represented by particular size fractions. We conclude that the differences between ash/charcoal size fractions were most likely primarily imposed by fuel source and secondarily by burning conditions. Size fractionation can therefore serve as a valuable tool to characterise the forest wildfire combustion products, as each fraction displays a narrower range of properties than the whole sample. We propose the mineral ash content of the fractions as criterion for selecting the appropriate number of fractions to analyse. [less ▲]

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See detailAn innovative non-animal chitosan hydrogel is able to restore the rheology of osteoarthritis synovial fluid ex vivo
Henrotin, Yves ULg; Rocasalbas, Guillem; Chausson, Mickaël et al

in Osteoarthritis and Cartilage (2017, April)

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See detailHypercalcemie par mutation inactivatrice du CYP24A1. Etude d'un cas et revue de la litterature.
Seidowsky, Alexandre; Villain, Cedric; Vilaine, Eve et al

in Néphrologie & Thérapeutique (2017)

We present the case of a family whose members have high levels of serum calcium (hypercalcaemia) by loss of function of the enzyme vitamin D 24-hydroxylase due to bi-allelic mutations in the CYP24A1 gene ... [more ▼]

We present the case of a family whose members have high levels of serum calcium (hypercalcaemia) by loss of function of the enzyme vitamin D 24-hydroxylase due to bi-allelic mutations in the CYP24A1 gene: c.443 T>C (p.Leu148Pro) and c.1187 G>A (p.Arg396Gln). 24-VITD hydroxylase is a key player in regulating the circulating calcitriol, its tissue concentration and its biological effects. Transmission is recessive. The estimated prevalence of stones in the affected subjects is estimated between 10 and 15%. The loss of peripheral catabolism of vitamin D metabolites in patients with an inactivating mutation of CYP24A1 is responsible for persistent high levels of 1,25-dihydroxyvitamin D especially after sun exposure and a charge of native vitamin D. Although there are currently no recommendations (French review) on this subject, this disease should be suspected in association with recurrent calcium stones with nephrocalcinosis, and a calcitriol-dependent hypercalcaemia with adapted low parathyroid hormone levels. Resistance to corticosteroid therapy distinguishes it from other calcitriol-dependent hypercalcemia. A ratio of 25-hydroxyvitamin D/24.25 hydroxyvitamin D>50, is in favor of hypercalcemia with vitamin D deficiency 24-hydroxylase. Genetic analysis of CYP24A1 should be performed at the second step. The current therapeutic management includes the restriction native vitamin D supplementation and the limitation of sun exposure. Biological monitoring will be based on serum calcium control and modulation of parathyroid hormone concentrations. [less ▲]

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See detailPerspective and priorities for improvement of parathyroid hormone (PTH) measurement - A view from the IFCC Working Group for PTH.
Sturgeon, Catharine M.; Sprague, Stuart; Almond, Alison et al

in Clinica Chimica Acta (2017), 467

Parathyroid hormone (PTH) measurement in serum or plasma is a necessary tool for the exploration of calcium/phosphate disorders, and is widely used as a surrogate marker to assess skeletal and mineral ... [more ▼]

Parathyroid hormone (PTH) measurement in serum or plasma is a necessary tool for the exploration of calcium/phosphate disorders, and is widely used as a surrogate marker to assess skeletal and mineral disorders associated with chronic kidney disease (CKD), referred to as CKD-bone mineral disorders (CKD-MBD). CKD currently affects >10% of the adult population in the United States and represents a major health issue worldwide. Disturbances in mineral metabolism and fractures in CKD patients are associated with increased morbidity and mortality. Appropriate identification and management of CKD-MBD is therefore critical to improving clinical outcome. Recent increases in understanding of the complex pathophysiology of CKD, which involves calcium, phosphate and magnesium balance, and is also influenced by vitamin D status and fibroblast growth factor (FGF)-23 production, should facilitate such improvement. Development of evidence-based recommendations about how best to use PTH is limited by considerable method-related variation in results, of up to 5-fold, as well as by lack of clarity about which PTH metabolites these methods recognise. This makes it difficult to compare PTH results from different studies and to develop common reference intervals and/or decision levels for treatment. The implications of these method-related differences for current clinical practice are reviewed here. Work being undertaken by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) to improve the comparability of PTH measurements worldwide is also described. [less ▲]

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See detailUncertainty quantification of Antarctic contribution to sea-level rise using the fast Elementary Thermomechanical Ice Sheet (f.ETISh) model
Bulthuis, Kevin ULg; Arnst, Maarten ULg; Pattyn, Frank et al

Conference (2017, April)

Uncertainties in sea-level rise projections are mostly due to uncertainties in Antarctic ice-sheet predictions (IPCC AR5 report, 2013), because key parameters related to the current state of the Antarctic ... [more ▼]

Uncertainties in sea-level rise projections are mostly due to uncertainties in Antarctic ice-sheet predictions (IPCC AR5 report, 2013), because key parameters related to the current state of the Antarctic ice sheet (e.g. sub-ice- shelf melting) and future climate forcing are poorly constrained. Here, we propose to improve the predictions of Antarctic ice-sheet behaviour using new uncertainty quantification methods. As opposed to ensemble modelling (Bindschadler et al., 2013) which provides a rather limited view on input and output dispersion, new stochastic methods (Le Maître and Knio, 2010) can provide deeper insight into the impact of uncertainties on complex system behaviour. Such stochastic methods usually begin with deducing a probabilistic description of input parameter uncertainties from the available data. Then, the impact of these input parameter uncertainties on output quantities is assessed by estimating the probability distribution of the outputs by means of uncertainty propagation methods such as Monte Carlo methods or stochastic expansion methods. The use of such uncertainty propagation methods in glaciology may be computationally costly because of the high computational complexity of ice-sheet models. This challenge emphasises the importance of developing reliable and computationally efficient ice-sheet models such as the f.ETISh ice-sheet model (Pattyn, 2015), a new fast thermomechanical coupled ice sheet/ice shelf model capable of handling complex and critical processes such as the marine ice-sheet instability mechanism. Here, we apply these methods to investigate the role of uncertainties in sub-ice-shelf melting, calving rates and climate projections in assessing Antarctic contribution to sea-level rise for the next centuries using the f.ETISh model. We detail the methods and show results that provide nominal values and uncertainty bounds for future sea- level rise as a reflection of the impact of the input parameter uncertainties under consideration, as well as a ranking of the input parameter uncertainties in the order of the significance of their contribution to uncertainty in future sea-level rise. In addition, we discuss how limitations posed by the available information (poorly constrained data) pose challenges that motivate our current research. [less ▲]

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See detailL’ÉCHOGRAPHIE EN SITUATION DE SOIN : STÉTHOSCOPE DU FUTUR POUR LE MÉDECIN GÉNÉRALISTE ?
Henrard, Gilles ULg; Froidcoeur, Xavier ULg; Schoffeniels, Colombe et al

in Revue Médicale de Liège (2017)

Ultrasound is presently emerging not only as a specialist-delegated diagnostic procedure, but also as a tool used by clinicians for guiding decision. If this paradigm shift has taken roots in places like ... [more ▼]

Ultrasound is presently emerging not only as a specialist-delegated diagnostic procedure, but also as a tool used by clinicians for guiding decision. If this paradigm shift has taken roots in places like emergency departments, initiatives are also set up here and there in general practice. The aim of this article is , through a literature review, to identify possible indications of ultrasound performed by the general practitioner and to initiate a discussion about the obstacles and opportunities associated with its introduction in Belgian General Practice settings. [less ▲]

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See detailCartographie de la disponibilité en eau et en éléments nutritifs des stations forestières de Wallonie
Wampach, Florent ULg; Lisein, Jonathan; Cordier, Sophie ULg et al

in FORÊT.NATURE (2017), avril-mai-juin(143), 47-60

Grâce aux données cartographiques de plus en plus nombreuses et disponibles, il est maintenant possible d'analyser l'adéquation essence-station à l'échelle d'un massif ou d'un cantonnement. A l'échelle ... [more ▼]

Grâce aux données cartographiques de plus en plus nombreuses et disponibles, il est maintenant possible d'analyser l'adéquation essence-station à l'échelle d'un massif ou d'un cantonnement. A l'échelle plus locale, cette nouvelle cartographie constitue un outil d'aide à l'interprétation des stations pour les gestionnaires, forestiers ou naturalistes. [less ▲]

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See detailDéploiement de dispositifs numériques au sein de nouvelles formes d’organisation : de l’émergence à la stabilisation
Jemine, Grégory ULg

in Sociologies Pratiques (2017), 34(1), 49-59

De plus en plus d’organisations du secteur des services s’équipent aujourd’hui de dispositifs numériques variés qui modifient les contextes et les contenus du travail. Ces outils sont présentés comme des ... [more ▼]

De plus en plus d’organisations du secteur des services s’équipent aujourd’hui de dispositifs numériques variés qui modifient les contextes et les contenus du travail. Ces outils sont présentés comme des ingrédients indispensables des modes managériales actuelles qui permettraient à divers dispositifs organisationnels promouvant la flexibilité et la mobilité de s’incarner. La présente contribution propose une étude des ressorts de l’émergence et de la stabilisation de ces dispositifs numériques qui émergent dans le cours de transformations organisationnelles. Nous montrons comment, dans une compagnie d’assurances, les dispositifs numériques sont mobilisés pour répondre à une volonté de « modernisation » de l’organisation et d’optimisation de l’espace de travail. [less ▲]

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See detailPrimary hypertrophic osteoarthropathy due to a novel SLCO2A1 mutation masquerading as acromegaly
Mangupli, Ruth; Daly, Adrian ULg; Cuauro, Elvia et al

in Endocrinology, Diabetes and Metabolism Case Reports (2017)

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See detailA Royal Head
Laboury, Dimitri ULg; Connor, Simon

in Ben-Tor, Amnon; Zuckerman, Sharon; Bechar, Shlomit (Eds.) et al Hazor VII. The 1990-2012 excavations. The Bronze Age (2017)

Publication / entry in an archaeological report of a greywacke royal head excavated in Tell Hazor, in stratum XIII, in the debris of the final destruction of the site (mid-thirteenth century BCE)

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See detailVitamin D supplementation in the prevention and management of major chronic diseases not related to mineral homeostasis in adults: research for evidence and a scientific statement from the European society for clinical and economic aspects of osteoporosis and osteoarthritis (ESCEO)
Cianferotti, Luisella; Bertoldo, Francesco; Bischoff-Ferrari, Heike et al

in Endocrine (2017), 56(2), 245-61

Introduction Optimal vitamin D status promotes skeletal health and is recommended with specific treatment in individuals at high risk for fragility fractures. A growing body of literature has provided ... [more ▼]

Introduction Optimal vitamin D status promotes skeletal health and is recommended with specific treatment in individuals at high risk for fragility fractures. A growing body of literature has provided indirect and some direct evidence for possible extraskeletal vitamin D-related effects. Purpose and Methods Members of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis have reviewed the main evidence for possible proven benefits of vitamin D supplementation in adults at risk of or with overt chronic extra-skeletal diseases, providing recommendations and guidelines for future studies in this field. Results and conclusions Robust mechanistic evidence is available from in vitro studies and in vivo animal studies, usually employing cholecalciferol, calcidiol or calcitriol in pharmacologic rather than physiologic doses. Although many cross-sectional and prospective association studies in humans have shown that low 25-hydroxyvitamin D levels (i.e., <50 nmol/L) are consistently associated with chronic diseases, further strengthened by a dose-response relationship, several meta-analyses of clinical trials have shown contradictory results. Overall, large randomized controlled trials with sufficient doses of vitamin D are missing, and available small to moderate-size trials often included people with baseline levels of serum 25-hydroxyvitamin D levels >50 nmol/L, did not simultaneously assess multiple outcomes, and did not report overall safety (e.g., falls). Thus, no recommendations can be made to date for the use of vitamin D supplementation in general, parental compounds, or non-hypercalcemic vitamin D analogs in the prevention and treatment of extra-skeletal chronic diseases. Moreover, attainment of serum 25-hydroxyvitamin D levels well above the threshold desired for bone health cannot be recommended based on current evidence, since safety has yet to be confirmed. Finally, the promising findings from mechanistic studies, large cohort studies, and small clinical trials obtained for autoimmune diseases (including type 1 diabetes, multiple sclerosis, and systemic lupus erythematosus), cardiovascular disorders, and overall reduction in mortality require further confirmation. [less ▲]

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See detailD’une victime à l’autre: Posture ou (im)posture victimaire?
Garcet, Serge ULg

in Revue de la Faculté de Droit de l'Université de Liège (2017), 2017/1

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See detailFluvial dike breaching due to overtopping: how different is it from dam breaching?
Rifai, Ismail; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

Conference (2017, April)

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See detailLessons learned from combined experimental and numerical modelling of urban floods
Archambeau, Pierre ULg; Bruwier, Martin ULg; Finaud-Guyot, Pascal et al

Conference (2017, April)

Field data for validating hydraulic models remain scarce, They are often limited to inundation extents and water marks, which provide little insights into the dynamic features of the flow in urbanized ... [more ▼]

Field data for validating hydraulic models remain scarce, They are often limited to inundation extents and water marks, which provide little insights into the dynamic features of the flow in urbanized floodplains, such as the discharge partition in-between the streets and the velocity fields. To address this issue, a unique experimental setup representing a whole urban district was built in the laboratory ICube in Strasbourg and the state-of-the-art shallow- water model Wolf 2D was tested against the experimental measurements (An'ault et al, 2016), The numerical model was also used to extend and refine the analysis of the laboratory observations. The experimental model (5 m >< 5 m) represents a square urban district with a total of l4 streets of different Widths and 49 intersections (crossroads). The inflow discharge can be controlled in each street individually and the outflow discharges were measured downstream of each street. The numerical model Wolf was developed at the University of Liege and has been extensively used in flood risk research (Beckers et al, 2013, Bruwier et al. 2015, Detrembleur et al. 2015). Several lessons could be learned from this combined experimental and numerical analysis. First, we found that the discharge partition in—between the streets is primarily controlled by the street widths. Second, although the standard shallow-water equations reproduce satisfactorily tnost of the flow characteristics, adding a turbulence model improves the prediction of the shape and length of the flow recirculations in the streets. Yet, this has little influence on the discharge partition because the computed recirculation widths are hardly affected by the turbulence model. The experiments and the numerical model also show that the water depths in the streets remain fairly constant in~between two intersections, while they drop suddenly downstream of each intersection as a result of complex flow interactions at the intersections. This hints that friction has little influence on the water depths obtained in the experiments. However, tailored numerical tests demonstrate that this is a direct consequence of the distorted nature of the experimental setup. Indeed, the ratio between the water depth and the street width is close to 1 in the experiments, while it would be at least one order of magnitude lower in real-world conditions, even for extreme floods. Finally, remote sensing data, such as digital elevation models, are generally available on a regular grid, which makes it convenient to use also a Cartesian grid for hydraulic modelling, We show here that the discretization of the geometry of the buildings on such a Cartesian grid has a major influence on the modelling accuracy (overestimation of the overall flow resistance). An extended shallow-water model based on non-isotropic porosity parameters is shown to improve substantially the prediction of the discharge partition in-between the streets. It is therefore considered as a valuable tool to advance urban flood modelling in practice. From the lessons learned here, we recommend that future research focuses on the design and exploitation of a less distorted experimental model, as well as on the analysis of extra flow processes such as transient conditions and interactions between overland flow and pressurized flow in underground passages. [less ▲]

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See detailTransition between symmetric and asymmetric flow in rectangular shallow reservoirs — a case of maximum dissipation?
westhoff, Martijn; Erpicum, Sébastien ULg; Archambeau, Pierre ULg et al

Conference (2017, April)

Shallow reservoirs are often used in hydraulic engineering as sediment traps or storage basins, Sedimentation within these reservoirs depends on the flow pattern, which in turn depends on the shape of the ... [more ▼]

Shallow reservoirs are often used in hydraulic engineering as sediment traps or storage basins, Sedimentation within these reservoirs depends on the flow pattern, which in turn depends on the shape of the reservoir. For short rectangular reservoirs, the main jet flows straight from the inlet to the outlet with on both sides identical recirculation zones. In longer reservoirs, however, the main jet reattaches to the side of the reservoir leading to a small and a large recirculation zone. Previous studies have found an empirical geometric relation describing the switch between these two different flow patterns. In this study, we demonstrate that this switch in flow pattern coincides with a maximization of energy dissipation in the shear layer between the main jet and the recirculation zones. To show this we described the power received from the jet by the recirculation zone as the product of a fluid-fluid friction coefficient and the square of the velocity difference times the shear velocity of the recirculation zone. This power is balanced by the bottom friction of the recirculation zone. Energy dissipation in the shear layer is then determined as the difference between the power performed by the jet and the power received by the recirculation zone. In this setup, energy dissipation is maximized by optimizing the friction coefficient. We show that for short reservoir lengths, energy dissipation is higher in the case of a symmetric flow pattern, while for longer reservoir the energy dissipation is higher for asymmetric flow patterns. The simulated switch between the two flow patterns appears to be very close to the empirical relation. This suggests that the flow pattem adapts in order to maximize energy dissipation between the jet and recirculation zones. The strength of this approach lies in the fact that no detailed knowledge of small scale processes is needed, while large scale structure formation can still be predicted. [less ▲]

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See detailA laser profilometry technique for monitoring fluvial dike breaching in laboratory experiments
Dewals, Benjamin ULg; Rifai, Ismail; Erpicum, Sébastien ULg et al

Conference (2017, April)

A challenging aspect for experimental modelling of fluvial dike breaching is the continuous monitoring of the transient breach geometry. In dam breaching cases induced by flow overtopping over the whole ... [more ▼]

A challenging aspect for experimental modelling of fluvial dike breaching is the continuous monitoring of the transient breach geometry. In dam breaching cases induced by flow overtopping over the whole breach crest (plane erosion), a side view through a glass wall is sufficient to monitor the breach formation. This approach can be ex- tended for 3D dam breach tests (spatial erosion) ifthe glass wall is located along the breach centreline. In contrast using a side view does not apply for monitoring fluvial dike breaching, because the breach is not symmetric in this case. We present a non-intrusive, high resolution technique to record the breach development in experimental models of fluvial dikes by means of a laser profilometry (Rifai et al. 2016). Most methods used for monitoring dam and dike breaching involve the projection of a pattern (fringes, grid) on the dam or dike body and the analysis of its deformation on images recorded during the breaching (e.g., Pickett et al. 201 1, Frank and Hager 2014). A major limitation of these methods stems from reflection on the water surface, particularly in the vicinity of the breach where the free surface is irregular and rippled. This issue was addressed by Spinewine et al. (2004), who used a single laser sheet so that reflections on the water surface were strongly limited and did not hamper the accurate processing of each image. We have developed a similar laser profilometry technique tailored for laboratory experiments on fluvial dike breaching. The setup is simple and relatively low cost. It consists of a digital video camera (resolution of 1920 >< 1080 pixels at 60 frames per second) and a swiping red diode 30 mW laser that enables the projection of a laser sheet over the dike body. The 2D image coordinates of each defomied laser profile incident on the dike are transformed into 3D object coordinates using the Direct Linear Transformation (DLT) algorithm. All 3D object coordinates computed over a swiping cycle of the laser are merged to generate a cloud of points. The DLT-based image processing method uses control points and reference axes, so that no prior knowledge is needed on the position, orientation and intrinsic characteristics of the camera, nor on the laser position. Refraction of the light and laser rays across the water surface needs to be taken into account, because the dike is partially submerged during the experiments. An ad hoc correction is therefore applied using the Snell-Descartes law. For dtis purpose, planar approximations are used to describe the shape of the water surface. In the presen- tation, we will discuss the resulting uncertainty and will detail the validation of the developed method based on configurations of known geometry with various complexity. The presented laser profilometry technique allows for a rapid non-intrusive measurement of the dike geometry evolution. It is readily available for laboratory experiments and has proven its performance (Rifai et al. 2017). Further adjustments are needed for its application to cohesive dike material due to the reduced visibility resulting from the higher turbidity of water. [less ▲]

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See detailDes "fabriques de mosquée" à Bruxelles?
Husson, Jean-François ULg

Article for general public (2017)

Le bourgmestre de Bruxelles a proposé la création de "fabriques de mosquées" pour encadrer l'action des lieux de culte musulmans. Cette carte blanche lui répond, en expliquant qu'un tel instrument existe ... [more ▼]

Le bourgmestre de Bruxelles a proposé la création de "fabriques de mosquées" pour encadrer l'action des lieux de culte musulmans. Cette carte blanche lui répond, en expliquant qu'un tel instrument existe déjà et que cela ne répondra par ailleurs pas à certaines inquiétudes exprimées. [less ▲]

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