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See detailUncertainty in biology: a computational modeling approach
Geris, Liesbet ULg; Gomez-Cabrero, David

Book published by Springer (2015)

Computational modeling of biomedical processes is gaining more and more weight in the current research into the etiology of biomedical problems and potential treatment strategies. Computational modeling ... [more ▼]

Computational modeling of biomedical processes is gaining more and more weight in the current research into the etiology of biomedical problems and potential treatment strategies. Computational modeling allows to reduce, refine and replace animal experimentation as well as to translate findings obtained in these experiments to the human background. However these biomedical problems are inherently complex with a myriad of influencing factors, which strongly complicates the model building and validation process. This book wants to address four main issues related to the building and validation of computational models of biomedical processes: 1. Modeling establishment under uncertainty 2. Model selection and parameter fitting 3. Sensitivity analysis and model adaptation 4. Model predictions under uncertainty In each of the abovementioned areas, the book discusses a number of key-techniques by means of a general theoretical description followed by one or more practical examples. This book is intended for graduate students and researchers active in the field of computational modeling of biomedical processes who seek to acquaint themselves with the different ways in which to study the parameter space of their model as well as its overall behavior. [less ▲]

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See detailIUVS observations of Nitric Oxide nightglow
Stiepen, Arnaud ULg; The IUVS team

Conference (2015, September)

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See detailContribution of the Finite Volume Point Dilution Method for measurement of groundwater fluxes in a fractured aquifer
Jamin, Pierre ULg; Goderniaux, Pascal; Bour, Olivier et al

Conference (2015, September)

The measurement of groundwater fluxes is the basis of all hydrogeological studies. Groundwater flux calculation with Darcy’s law from piezometric gradient measurements and estimation of hydraulic ... [more ▼]

The measurement of groundwater fluxes is the basis of all hydrogeological studies. Groundwater flux calculation with Darcy’s law from piezometric gradient measurements and estimation of hydraulic conductivity with pumping/slug tests may lead to cumulated errors on spatial variability, in particular in heterogeneous contexts such as fractured aquifers. Alternative methods, such as point dilution tracer tests to obtain a direct measurement of local groundwater fluxes, are promising. In this study classical Point Dilution Method (PDM) and Finite Volume Point Dilution Method (FVPDM) are compared on the fractured crystalline aquifer of Ploemeur, France. The manipulation includes the first use of the FVPDM in a fractured aquifer using a double packer. This configuration limits the vertical extent of the tested zone to target a precise fracture zone of the aquifer. The result of this experiment wasa continuous monitoring of groundwater flux that lasted more than 4 days. Measurements of groundwater flow rate in the fracture (Qt) by PDM only provide good estimates if the mixing volume (Vw) (volume of water in which the tracer is mixed) is known precisely. Conversely, FVPDM allows for an independent estimation of Vw and Qt, leading to better precision in case of complex experimental setup such as this one. The precision of PDM does not depend upon the duration of the experiment while FVPDM may require long experimental duration to guarantee a precise result. Classical PDM should be used to rapidly estimate the groundwater flux using a simple experimental setup. However, FVPDM is a more precise method with great potential for development but it may require a longer experiment duration to achieve high precision if the groundwater flux investigated islow and/or the mixing volume is large. [less ▲]

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See detailDiscovery of Diffure Aurora on Mars
Stiepen, Arnaud ULg; Schneider; Jain et al

Conference (2015, September)

The Imaging Ultraviolet Spectrograph (IUVS, McClintock et al., 2014) onboard the MAVEN spacecraft has discovered diffuse aurora in Mars’ northern hemisphere spanning a wide range of geographic latitudes ... [more ▼]

The Imaging Ultraviolet Spectrograph (IUVS, McClintock et al., 2014) onboard the MAVEN spacecraft has discovered diffuse aurora in Mars’ northern hemisphere spanning a wide range of geographic latitudes and longitudes (Figure 1). This widespread aurora differs from the small auroral patches discovered by the SPICAM instrument onboard the Mars Express spacecraft (Bertaux et al., 2005; Leblanc et al., 2008; Gérard et al., submitted; Soret et al., submitted) restricted to regions of crustal magnetic fields in the southern hemisphere. Furthermore, the northern diffuse aurora appears to peak at altitudes below 100 km, while the crustal field aurora peaked around 120 km. [less ▲]

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See detailFirst Results From MAVEN’s Imaging UV Spectrograph
Schneider; McClintock; Stewart et al

Conference (2015, September)

We report the first results from The Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile and EvolutioN (MAVEN) spacecraft orbiting Mars. The instrument is accomplishing its ... [more ▼]

We report the first results from The Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile and EvolutioN (MAVEN) spacecraft orbiting Mars. The instrument is accomplishing its goals of characterizing the atmospheric composition and structure, enabling studies of atmospheric escape that will contribute to our understanding of Mars’ atmospheric evolution. In addition, the instrument has made unexpected discoveries concerning meteor showers, aurora and nightglow on Mars. [less ▲]

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See detailTwinkling Lights in the Nightside Upper Atmosphere: How Nightglow Contributes to our Understanding of Global Dynamics
Brecht, Amanda; Bougher, S.; Stiepen, Arnaud ULg et al

Conference (2015, September)

Upper atmospheres of planets continuously emit photons in the UV, Visible, and IR regions of the electromagnetic spectrum. Some of these emissions are classified as airglow, which includes dayglow and ... [more ▼]

Upper atmospheres of planets continuously emit photons in the UV, Visible, and IR regions of the electromagnetic spectrum. Some of these emissions are classified as airglow, which includes dayglow and nightglow. There are several mechanisms to create these emissions, but this presentation will focus on nightglow emissions resulting from photochemistry of neutral components. These neutral components originate on the dayside and are transported from the dayside to the nightside of a planet, where they subsequently undergo chemical reactions yielding nightglow. Nightglow emissions serve as effective tracers for planetary middle and upper atmosphere global wind systems due to their variable peak brightness and spatial distributions. The main planetary focus for this presentation will be on Mars and Venus’ atmospheres, due to the similar chemical constituents which populate their upper atmospheres. Currently, NO UV nightglow has been observed (e.g. Venus Express, Mars Express) on both Venus and Mars, while O2 IR nightglow has only been observed on Venus but is predicted to be seen on Mars. The observations show variations in time and location (latitude, local time, and altitude). The locations of the maximum nightglow intensities on each planet are different, but are supportive of the general picture of these two planet’s global circulation patterns. Model implications for both nightglows on both planets can provide valuable insight and understanding of the dynamical and chemical processes creating the nightglow emission variability. Two three-dimensional general circulation models will be utilized: the Venus Thermospheric General Circulation Model (VTGCM) and the Mars Global Ionosphere-Thermosphere Model (MGITM). The model output will be compared to nightglow datasets for each planet individually and planet to planet, to contrast the variations of the nightglow features and the underlying drivers for those variations. [less ▲]

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See detailThe use of the Vadose Zone Experimental Setup as an innovative in situ characterization method for the vadose zone: a case study at an industrial contaminated site in Belgium
Fernandez de Vera, Natalia ULg; Beaujean, Jean ULg; Jamin, Pierre ULg et al

Conference (2015, September)

The development of protection and remediation plans for contaminated soil and groundwater require a detailed understanding of the transport of pollutants in the subsurface. However, such understanding is ... [more ▼]

The development of protection and remediation plans for contaminated soil and groundwater require a detailed understanding of the transport of pollutants in the subsurface. However, such understanding is affected by the lack of spatial and temporal coverage provided by the current in situ characterization technologies. A new system has been developed in order to overcome such limitations. The vadose zone experimental setup is a new development combining cross-hole geophysics and the Vadose Zone Monitoring System (VMS). In cross-hole geophysics, an injection of an electrical current using electrodes installed in vertical boreholes is triggered. From measured potential differences, spatial patterns related with subsurface heterogeneities, water content and solute concentrations are inferred. The VMS allows continuous measurements of water content at different depths of the vadose zone, as well as water sampling. The system is formed by a flexible sleeve containing monitoring units along its depth which is installed in a slanted borehole. The system was installed at a former industrial site in Belgium, where soil and groundwater are contaminated with BTEX, PAH, and heavy metals. Two VMS were installed in two slanted boreholes on site, together with four vertical boreholes containing electrodes for geophysical measurements. The site was initially monitored under natural recharge conditions. Water content sensors located along the VMS registered fast wetting and draining reactions to rainfall events followed by the activation of water transport through fractures. Results from soil water samples show continuous evolution of water chemistry with depth, due to disequilibrium between infiltrated water and the hydrochemical conditions in the unsaturated zone. Subsequently, a saline tracer was injected in the surface. The transport of the tracer in the subsurface was monitored via cross-hole and surface geophysics. Results from imaging reflect the evolution of a plume through vertical and lateral transport and dilution. [less ▲]

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See detailNudge and the Law: A European Perspective
Sibony, Anne-Lise ULg; Alemanno, Alberto

Book published by Hart Publishing (2015)

Behavioural sciences provide a better understanding of human decision-making. Increasingly, governments around the world are keen to rely on these insights for reshaping public interventions in a wide ... [more ▼]

Behavioural sciences provide a better understanding of human decision-making. Increasingly, governments around the world are keen to rely on these insights for reshaping public interventions in a wide range of policy areas such as energy, health, financial services and data protection. When policy-making meets behavioural sciences, effective, low- cost and choice preserving regulations can emerge in the form of default rules, smart disclosure and simplification requirements. While behaviourally-informed regulation has a huge potential, it also attracts legitimacy and practicability concerns. Nudge and the Law explores the legal implications of the emergent phenomenon of behavioural regulation by focusing on the challenges and opportunities it may offer to EU policy-making and beyond [less ▲]

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See detailControlling factors and occurrence of inorganic and organic compounds in groundwater of urban and industrial areas
Gesels, Julie ULg; Dollé, Fabien ULg; Leclercq, Julie et al

Conference (2015, September)

A relatively extensive survey of groundwater contaminants is performed in urban and industrial contexts, at the regional scale (Walloon Region of Belgium), outside spots of contamination related to ... [more ▼]

A relatively extensive survey of groundwater contaminants is performed in urban and industrial contexts, at the regional scale (Walloon Region of Belgium), outside spots of contamination related to contaminated sites. More specifically, the most detected inorganic trace elements and organic contaminants are identified and their levels of occurrence are described statistically. Mechanisms that can explain their occurrence in groundwater are discussed. From a more pragmatic point of view, the data set has been also used to derive upper limits of pollutant background concentrations to be used in decision-making related to the management of contaminated groundwater in urban and industrial environments. The results presented are based on 243 samples from 8 sectors located in different geological contexts and different urban and industrial contexts. Each groundwater sample was analyzed for 19 inorganic trace elements, 61 organic micro-pollutants and 10 major and minor elements. Five physico-chemical parameters were measured in the field, at the time of sampling to determine the environmental conditions prevailing in groundwater. For comparison, existing groundwater analyses in natural context, available for the entire Walloon Region, were compiled from several databases. Cumulative distribution function plots allow comparing the distributions of inorganic trace elements in urban and industrial sectors to those obtained at the scale of the entire Walloon region. Cumulative distribution function plots are also used to compare the distribution of the inorganic trace elements in the different lithologies, in urban and industrial contexts. The composition of groundwater is altered in urban and industrial sectors with increased concentrations for most inorganic trace elements and organic contaminants. Anthropogenic influence is not limited to inputs of pollutants but also to alterations of subsurface environmental conditions, in particular redox conditions, resulting in the mobilization of pollutants. The influence of lithology is also marked in the data set. [less ▲]

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See detailA new hybrid approach for modelling groundwater flow in karst aquifers
Willems, Thibault ULg; Hakoun, Vivien ULg; Renard, Philippe et al

Conference (2015, September)

Groundwater flow modelling in karst aquifers represents a real challenge that requires adapted methods. The applicability of an innovative hybrid approach for modelling groundwater flow in karst aquifers ... [more ▼]

Groundwater flow modelling in karst aquifers represents a real challenge that requires adapted methods. The applicability of an innovative hybrid approach for modelling groundwater flow in karst aquifers, namely the Hybrid Finite Element Mixing Cell (HFEMC) method, is evaluated. The hybrid approach consists in combining a classical finite element (FE) model, to model slow flow in the rock matrix, with spatially distributed lumped reservoirs, to model fast flow in the karst conduits network. Water exchanges between the rock matrix and the conduits network are accounted for by means of an internal Fourier boundary conditions (BC). This BC (1st order exchange relation) allows to control the magnitude of water transfers between fast and slow flow domains. We tested the applicability of the HFEMC method on a schematic synthetic domain and on a real karst system. In the synthetic case analysis, we discussed dynamic processes of groundwater storage occurring in the karst system during a recharge pulse. The study focuses on the influence of selected parameters on representative variables such as the discharge curve of the karst system or pressure and mass transfers between conduits and rock matrix sub-domains. In this way, an inversion of the hydraulic gradient between karst conduits and the surrounding rock matrix is shown to occur during the recharge pulse. This phenomenon results in a temporary storage of water from conduits to the rock matrix, which impacts the modelled discharge curve. The first test performed on a real study site, the Noiraigue spring karst system (Jura mountains, Switzerland), exemplify the use of two separated lumped reservoirs for describing the conduits network, which allows to consider two base levels in the karst system. It also points out the challenges to face when modelling a complex natural karst system with the HFEMC approach. The results obtained show that the HFEMC approach is a good candidate to model groundwater flow in karst aquifers. [less ▲]

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See detailSimple Median-Based Method for Stationary Background Generation Using Background Subtraction Algorithms
Laugraud, Benjamin ULg; Pierard, Sébastien ULg; Braham, Marc ULg et al

in New Trends in Image Analysis and Processing - ICIAP 2015 Workshops (2015, September)

The estimation of the background image from a video sequence is necessary in some applications. Computing the median for each pixel over time is effective, but it fails when the background is visible for ... [more ▼]

The estimation of the background image from a video sequence is necessary in some applications. Computing the median for each pixel over time is effective, but it fails when the background is visible for less than half of the time. In this paper, we propose a new method leveraging the segmentation performed by a background subtraction algorithm, which reduces the set of color candidates, for each pixel, before the median is applied. Our method is simple and fully generic as any background subtraction algorithm can be used. While recent background subtraction algorithms are excellent in detecting moving objects, our experiments show that the frame difference algorithm is a technique that compare advantageously to more advanced ones. Finally, we present the background images obtained on the SBI dataset, which appear to be almost perfect. The source code of our method can be downloaded at http://www.ulg.ac.be/telecom/research/sbg . [less ▲]

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See detailDermatophytosis, Trends in Epidemiolgy and Diagnostic Approach
HAYETTE, Marie-Pierre ULg; SACHELI, Rosalie ULg

in Current Fungal Infections report (2015), 9(3), 164-179

Dermatophytes are among the common fungal agents implicated in superficial skin infections. The anthropophilic dermatophyte Trichophyton rubrum is still the most frequent causative agent worldwide but the ... [more ▼]

Dermatophytes are among the common fungal agents implicated in superficial skin infections. The anthropophilic dermatophyte Trichophyton rubrum is still the most frequent causative agent worldwide but the prevalence of several species of dermatophytes varies through different areas around the world. This review summarizes the current status of dermatophytes infection in Europe, Africa, Asia and America and gives an overview of the molecular biology laboratory methods currently available for the diagnosis of dermatomycoses. [less ▲]

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See detailChanging public viewpoints on wind energy development in Belgium
Vanderheyden, Vincent ULg; Schmitz, Serge ULg

in Abstracts. Energy Landscapes: Perception, Planning, Participation and Power. European Conference of the Landscape Research Group, Dresden, 16‐18 September 2015 (2015, September)

The amount of wind turbines has increased exponentially in Belgium in the last eight years (175 in 2007, 771 in 2015). During this period, especially in the last two years, critics of this energy have ... [more ▼]

The amount of wind turbines has increased exponentially in Belgium in the last eight years (175 in 2007, 771 in 2015). During this period, especially in the last two years, critics of this energy have become more organised, virulent, and active in delaying or stopping many projects. The landscape impact of wind energy is central to their arguments. We wonder if people’s attitudes towards wind turbines and landscape changed in the last years in Belgium and how they changed. This paper compares public perception of wind energy in two researches about landscape perception. The two studies used slightly different methodologies but with similarities in the designs, allowing some comparisons. The first research (2007‐2009) aimed to study the perceived landscape impact and the social acceptance of wind turbines in Belgium. 1542 Belgians were surveyed about their landscape preferences using a photo‐questionnaire, including some pictures with wind turbines. 75 stakeholders of wind energy projects were also interviewed. The second research (2012‐2014) aimed to examine deeper the landscape preferences among 54 residents in three areas in Wallonia where wind turbines are present, using the previous photographs. During the conduct of the first research, changing attitudes were already observed. People had become more familiar with wind turbines and were less reluctant. The symbolic positive aspect of wind energy was highlighted seven years ago. This view continues. However, people seem more categorical in their viewpoint. All respondents have now been confronted to wind energy, which was not the case seven years ago. Some persons are not against wind farms but their increase in number start to overwhelm them. Others point they get used to the turbines, as long as they are not too many and too close. The huge increase in wind farms in the last seven years has changed the acceptance of wind energy. Some doubts about the real efficiency of this energy also shaped the attitudes. [less ▲]

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See detailRELY – short term scientific missions
Schmitz, Serge ULg

in Abstracts. Energy Landscapes: Perception, Planning, Participation and Power. European Conference of the Landscape Research Group, Dresden, 16‐18 September 2015 (2015, September)

The COST Action TU1401 ‘Renewable Energy and Landscape Quality’ ('RELY') encourages Short Term Scientific Missions (STSMs). This Action investigates “the inter‐relationships between renewable energy ... [more ▼]

The COST Action TU1401 ‘Renewable Energy and Landscape Quality’ ('RELY') encourages Short Term Scientific Missions (STSMs). This Action investigates “the inter‐relationships between renewable energy production and landscape quality, and the role of public participation for the acceptance of renewable energy systems”. STSMs are exchange visits from five working days until three months that are aiming to strengthen the existing networks by allowing individual scientists to go to an institution or laboratory in other COST country to foster collaboration and contribute to the scientific objectives of the COST Action. Each year of the COST Action TU1401, there are up to six STSMs to be awarded. The financial support is a contribution to the costs of a STSM. A grant (maximum 2500€ depending on the duration of the stay) covers travel and subsistence. We invite researchers, especially early stage researchers, to participate in a STSM. The selection of STSM applicants is based on the scientific scope of the STSM application that must be in line with the Cost Action TU1401 objectives. This short communication aims to inform of the next calls and presents the result of the 2015 call. [less ▲]

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See detailLes figures maternelles dans le Roman en prose de Guillaume d'Orange
Henrard, Nadine ULg

in Laurent, Françoise (Ed.) Le monde entour et environ. La geste, la route et le livre (2015)

Detailed reference viewed: 23 (7 ULg)
See detailGalland épigraphiste et philologue classique
Famerie, Etienne ULg

in Bauden, Frédéric; Waller, Richard (Eds.) Actes du Colloque "Antoine Galland (1646-1715) : orientaliste, antiquaire, numismate, humaniste" (2015, September)

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See detailPlasma riche en plaquettes pour le traitements de lésions tendineuses
Kaux, Jean-François ULg; Drion, Pierre ULg; Croisier, Jean-Louis ULg et al

in Journal de Réadaptation Médicale (2015), 35(3), 181-191

Objectives: The restorative properties of platelets, through the local release of growth factors, are used in various medical areas. This article reviews fundamental and clinical research relating to ... [more ▼]

Objectives: The restorative properties of platelets, through the local release of growth factors, are used in various medical areas. This article reviews fundamental and clinical research relating to platelet-rich plasma applied to tendinous lesions. Materials and method: Articles in French and English, published between 1 January 2012 and 30 September 2014 dealing with PRP and tendons were searched for using the Medline and Scopus data bases. Results: Forty-seven articles were identified which addressed pre-clinical and clinical studies: 27 relating to in vitro and in vivo animal studies and 20 relating to human studies. Of these, 5 addressed lateral epicondylitis, 2 addressed rotator cuff tendinopathies, 10 dealt with patellar tendinopathies and 3 looked at Achilles tendinopathies. Conclusions: The majority of pre-clinical studies show that PRP stimulates the tendon's healing process. However, clinical series remain more controversial and level 1, controlled, randomised studies are still needed. [less ▲]

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See detailCoupled modeling of Excavation Damaged Zone in Boom clay: Strain localization in rock and distribution of contact pressure on the gallery’s lining
Salehnia, Fatemeh ULg; Collin, Frédéric ULg; Li, Xiang Ling et al

in Computers and Geotechnics (2015), 69

Around galleries excavated at depth in geological media, the creation of a damaged zone with significant irreversible deformation is generally unavoidable. In the case of a geological disposal system for ... [more ▼]

Around galleries excavated at depth in geological media, the creation of a damaged zone with significant irreversible deformation is generally unavoidable. In the case of a geological disposal system for high-level radioactive waste, the resulting change in the host rock properties in this damaged zone may potentially be important with respect to the long-term evolution and the performance of that system. In this context, predicting the extent of the so-called Excavation Damaged Zone (EDZ) and, possibly, the fractures' network topology remains a challenge. This study is aimed to simulate numerically the extension of this zone at the large scale's excavation, around the Connecting gallery (HADES URL, Mol, Belgium), in Boom clay host rock through analyzing the evolution of strain localization in shear bands mode. To realistically model the involved phenomena, the concrete lining is considered on the gallery wall highlighting its impacts on the evolution of convergence and EDZ around the gallery. The focus of the current paper is made on analyzing the coupled hydro-mechanical behavior of Boom clay host rock during and after the gallery excavation with respect to the evolution of localized shear bands around the gallery. This study is accompanied by the analysis of the contact mechanism on the interface between the clay massive and the lining. The obtained results reveal some interesting features regarding the contact phenomenon relatively to the evolution pattern of shear bands within the clay around the gallery. To assess the reliability of the proposed approach, a discussion on some in-situ observations during the gallery's construction is also performed based on which a good agreement is found between the in-situ evidence and simulated results. [less ▲]

Detailed reference viewed: 27 (9 ULg)