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See detailMapping the dependency of crops on pollinators in Belgium
Jacquemin, Floriane ULg; Violle, Cyrille; Rasmont, Pierre et al

in One Ecosystem (2017)

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See detailBuilding flow and transport models with electrical resistivity tomography data
Gottschalk, Ian; Hermans, Thomas ULg; Knight, Rosemary et al

Poster (2017, July 26)

Aquifer recharge and recovery (ARR) is the process of enhancing natural groundwater resources and recovering water for later use by constructing engineered conveyances. Insufficient understanding of ... [more ▼]

Aquifer recharge and recovery (ARR) is the process of enhancing natural groundwater resources and recovering water for later use by constructing engineered conveyances. Insufficient understanding of lithological heterogeneity at ARR sites often hinders attempts to predict where and how quickly infiltrating water will flow in the subsurface, which can adversely affect the quality and quantity of available water in the ARR site. In this study, we explored the use of electrical resistivity tomography (ERT) to assist in characterizing lithological heterogeneity at an ARR site, so as to incorporate it into a flow and contaminant transport model. In this case, we had non-collocated well core log data and ERT data from a full-scale ARR basin. We compared three independent methods for producing conditional lithology-resistivity probability distributions: 1) a search template to relate the nearest logged well lithologies with ERT resistivity panels, given search criteria; 2) a maximum likelihood estimation (MLE) to match bimodal normal distributions to the histogram of each ERT line; and 3) variogram-based lithology indicator simulations constrained to well data. Each approach leverages Bayes’ Rule to estimate lithology probability given electrical resistivity. The simplest approach (method 1) yields an erroneous conditional probability function where sand dominates the conditional probability at nearly all resistivities, due in part to the strong presence of sand in the wells nearest the ERT lines. The approaches using MLE and lithology simulations (methods 2 and 3) produce similar, more realistic lithofacies probability functions. The range of resistivities where clay and sand overlap differs between methods 2 and 3: ranging between 100 and 200 ohm-m for method 2, and between 30 and 50 ohm-m for the method 3. These differences affect the posterior lithology distributions in multiple point geostatistical (MPS) simulations, and in turn, predictions of flow from models which integrate these results. To test the models, we can compare measured breakthrough times of recharged water at the site to groundwater flow simulation results using the lithofacies models created by each method. The methods described here can inform the integration of non-collocated geophysical data into a variety of applications. [less ▲]

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See detailEvaluating model simulations of 20th century sea-level rise. Part 1: Global mean sea-level change
Slangen, A.; Meyssignac, B.; Agosta, Cécile ULg et al

in Journal of Climate (2017)

Sea-level change is one of the major consequences of climate change and is projected to affect coastal communities around the world. Here, we compare Global Mean Sea-Level (GMSL) change estimated by 12 ... [more ▼]

Sea-level change is one of the major consequences of climate change and is projected to affect coastal communities around the world. Here, we compare Global Mean Sea-Level (GMSL) change estimated by 12 climate models from the 5th phase of the World Climate Research Programme’s Climate Model Intercomparison Project (CMIP5) to observational estimates for the period 1900-2015. We analyse observed and simulated individual contributions to GMSL change (thermal expansion, glacier mass change, ice sheet mass change, landwater storage change) and compare the summed simulated contributions to observed GMSL change over the period 1900-2007 using tide gauge reconstructions, and over the period 1993-2015 using satellite altimetry estimates. The model-simulated contributions allow us to explain 50 ± 30% (uncertainties 1.65σ unless indicated otherwise) of the mean observed change from 1901-1920 to 1988-2007. Based on attributable biases between observations and models, we propose to add a number of corrections, which result in an improved explanation of 75 ± 38% of the observed change. For the satellite era (1993-1997 to 2011-2015) we find an improved budget closure of 102 ± 33% (105 ± 35% when including the proposed bias corrections). Simulated decadal trends over the 20th century increase, both in the thermal expansion and the combined mass contributions (glaciers, ice sheets and landwater storage). The mass components explain the majority of sea-level rise over the 20th century, but the thermal expansion has increasingly contributed to sea-level rise, starting from 1910 onwards and in 2015 accounting for 46% of the total simulated sea-level change. [less ▲]

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See detailThe effect of initial water distribution and spatial resolution on the interpretation of ERT monitoring of water infiltration
Dumont, Gaël ULg; Pilawski, Tamara ULg; Robert, Tanguy et al

Poster (2017, July 25)

A better understanding of the water balance of a landfill is crucial for its management, as the waste water content is the main factor influencing the biodegradation process of organic waste. In order to ... [more ▼]

A better understanding of the water balance of a landfill is crucial for its management, as the waste water content is the main factor influencing the biodegradation process of organic waste. In order to investigate the ability of long electrical resistivity tomography (ERT) profiles to detect zones of high infiltration in a landfill cover layer, low resolution time lapse data were acquired during a rainfall event. Working at low resolution allows to cover large field areas but with the drawback of limiting quantitative interpretation. In this contribution, we use synthetic modeling to quantify the effect of the following issues commonly encountered when dealing with field scale ERT data: (i) the effect of low resolution on electrical resistivity changes interpretation, (ii) the effect of the original heterogeneous resistivity distribution on the observed relative resistivity changes, (iii) the need for temperature and pore fluid conductivity data in order to compute water content and absolute changes of water content, and (iv) the interpretation error commonly made while neglecting the dilution effect during fresh water infiltration. Firstly, due to the lack of spatial resolution, the regularized inversion process yields a smoothed distribution of resistivity changes that fail to detect small infiltration zones and yields an overestimation of the infiltration depth and an underestimation of the infiltrated volume in large infiltration areas. Secondly, the analysis of relative changes, as commonly used in literature, is not adequate when the background water content is highly heterogeneous. In such a case, relative changes reflect both the initial water content distribution and the observed changes. Thirdly, the computation of absolute water content changes better reflects the infiltration pattern, but requires spatially distributed temperature and pore fluid conductivity input data. Lastly, the dilution effect, if not considered, leads to an underestimation of the infiltrated volume. Taking into account these elements, we extracted the maximum amount of information from our field data without over-interpreting the results. This allowed the detection of larger infiltration areas possibly responsible for a large part of the annual water infiltration and landfill gas loss. [less ▲]

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See detailShape and spin determination of Barbarian asteroids
Devogele, Maxime ULg; Tanga, P.; Bendjoya, P. et al

in Astronomy and Astrophysics (2017)

The so-called Barbarian asteroids share peculiar, but common polarimetric properties, probably related to both their shape and composition. They are named after (234) Barbara, the first on which such ... [more ▼]

The so-called Barbarian asteroids share peculiar, but common polarimetric properties, probably related to both their shape and composition. They are named after (234) Barbara, the first on which such properties were identified. As has been suggested, large scale topographic features could play a role in the polarimetric response, if the shapes of Barbarians are particularly irregular and present a variety of scattering/incidence angles. This idea is supported by the shape of (234) Barbara, that appears to be deeply excavated by wide concave areas revealed by photometry and stellar occultations. Aims. With these motivations, we started an observation campaign to characterise the shape and rotation properties of Small Main- Belt Asteroid Spectroscopic Survey (SMASS) type L and Ld asteroids. As many of them show long rotation periods, we activated a worldwide network of observers to obtain a dense temporal coverage. Methods. We used light-curve inversion technique in order to determine the sidereal rotation periods of 15 asteroids and the con- vergence to a stable shape and pole coordinates for 8 of them. By using available data from occultations, we are able to scale some shapes to an absolute size. We also study the rotation periods of our sample looking for confirmation of the suspected abundance of asteroids with long rotation periods. Results. Our results show that the shape models of our sample do not seem to have peculiar properties with respect to asteroids with similar size, while an excess of slow rotators is most probably confirmed. [less ▲]

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See detailModèles de porosité pour les inondations urbaines
Dewals, Benjamin ULg; Bruwier, Martin ULg; El Saeid Mustafa, Ahmed Mohamed ULg et al

Scientific conference (2017, July 25)

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See detailHARMONIC BALANCE COMPUTATION OF THE NONLINEAR FREQUENCY RESPONSE OF A THIN PLATE
Lee, Jongsuh ULg; Kerschen, Gaëtan ULg; Detroux, Thibaut ULg

Conference (2017, July 24)

The harmonic balance method (HBM) is used to investigate the dynamical behavior of the geometrical nonlinear plate. The middle plane displacements are included in the plate in which the equations of ... [more ▼]

The harmonic balance method (HBM) is used to investigate the dynamical behavior of the geometrical nonlinear plate. The middle plane displacements are included in the plate in which the equations of motion are developed by the principle virtual work. Moreover, the nonlinear frequency response curves, or NFRCs, are obtained by a continuation method. [less ▲]

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See detailComprehensive Ion Mobility Calibration Strategies based on Synthetic Polymers
Haler, Jean ULg; Kune, Christopher ULg; Chirot, Fabien et al

Conference (2017, July 24)

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See detailSelf-assembly processes of superparamagnetic colloids in a quasi-two-dimensional system
Rojas, Nicolas; Darras, Alexis ULg; Lumay, Geoffroy ULg

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2017), 96(1), 012608

Superparamagnetic colloids gather depending on the magnitude of the magnetic field applied, forming chains and ribbons in a quasi-two-dimensional chamber. The results presented in this work are in good ... [more ▼]

Superparamagnetic colloids gather depending on the magnitude of the magnetic field applied, forming chains and ribbons in a quasi-two-dimensional chamber. The results presented in this work are in good agreement with recent experimental multistable data for the mean length of the aggregates in thermodynamic equilibrium. [less ▲]

See detailDual-specificity-phosphatase 3 (DUSP3) deletion promotes liver inflammation and high fat diet-induced hepatocellular carcinoma
Jacques, Sophie ULg; Arjomand, Arash ULg; Vandereyken, Maud ULg et al

Poster (2017, July 24)

Overweight and obesity are considered as risk factors for hepatocellular carcinoma (HCC) development. The mechanisms by which obesity promotes liver inflammation are however poorly understood. We recently ... [more ▼]

Overweight and obesity are considered as risk factors for hepatocellular carcinoma (HCC) development. The mechanisms by which obesity promotes liver inflammation are however poorly understood. We recently generated a full DUSP3 knockout (KO) mouse. The obtained mice were born normal with no spontaneous phenotype. However, while aging, DUSP3-KO mice became obese and developed hepatosteatosis. The phenotype was exacerbated under high fat diet (HFD). Furthermore, when treated with diethylnitrosamine (DEN) procarcinogen, DUSP3-KO mice developed HCC faster than WT littermates. The combination of DEN with HFD accelerated the onset of HCC development in these mice compared to WT mice. This was associated with increased systemic levels of several metabolites and with hyperphosphorylation of the insulin-like growth factor receptor I. [less ▲]

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See detailFunctional and structural characterisation of the Arabidopsis thaliana HMA4 protein
Lekeux, Gilles ULg; Laurent, Clémentine; Xiao, Zhiguang et al

Poster (2017, July 24)

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See detailReproductivity and egg quality of H’Mong chicken
Nguyen Van Duy, ULg; Nguyen Thi Phuong; Vu Dinh Ton et al

Scientific conference (2017, July 21)

This study was carried out at the experimental farm of Vienam National University of Agriculture (VNUA) during six months from August, 2016 to February, 2017. H'mong chickens were raised in three plots in ... [more ▼]

This study was carried out at the experimental farm of Vienam National University of Agriculture (VNUA) during six months from August, 2016 to February, 2017. H'mong chickens were raised in three plots in order to observe reproductive performane and egg quality. The results showed that productive performance of H'mong chickens was low in comparison with other local breeds. On average, the first egg laying age was 151.67 days when their body weight was 1323.8 grams. Twenty two to forty two week-old hens resulted in the average reproductive performane as 24,12 eggs/hen, laying rate as 17.23 percents, and FCR as 6.58 kg/10 eggs. Egg quality of H'mong chickens conformed to all standards of high-quality local eggs. [less ▲]

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See detailTypical versus delayed speech onset influences verbal reporting of autistic interests
Chiodo, Liliane ULg; Majerus, Steve ULg; Mottron, Laurent

in Molecular Autism (2017)

The distinction between autism and Asperger syndrome has been abandoned in the DSM-5. However, this clinical categorization largely overlaps with the presence or absence of a speech onset delay which is ... [more ▼]

The distinction between autism and Asperger syndrome has been abandoned in the DSM-5. However, this clinical categorization largely overlaps with the presence or absence of a speech onset delay which is associated with clinical, cognitive, and neural differences. It is unknown whether these different speech development pathways and associated cognitive differences are involved in the heterogeneity of the restricted interests that characterize autistic adults. [less ▲]

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See detailAcromegaly at diagnosis in 3173 patients from the Liege Acromegaly Survey (LAS) database.
PETROSSIANS, Patrick ULg; Daly, Adrian ULg; Natchev, Emil et al

in Endocrine-Related Cancer (2017)

Acromegaly is a rare disorder caused by chronic growth hormone (GH) hypersecretion. While diagnostic and therapeutic methods have advanced, little information exists on trends in acromegaly ... [more ▼]

Acromegaly is a rare disorder caused by chronic growth hormone (GH) hypersecretion. While diagnostic and therapeutic methods have advanced, little information exists on trends in acromegaly characteristics over time. The Liege Acromegaly Survey (LAS) database, a relational database, is designed to assess the profile of acromegaly patients at diagnosis and during long-term follow-up at multiple treatment centers. The study population consisted of 3173 acromegaly patients from ten countries; 54.5% were female. Males were significantly younger at diagnosis than females (43.5 vs. 46.4 years; p<0.001). The median delay from first symptoms to diagnosis was two years longer in females (p=0.015). Ages at diagnosis and first symptoms increased significantly over time (p<0.001). Tumors were larger in males than females (p<0.001); tumor size and invasion were inversely related to patient age (p<0.001). Random GH at diagnosis correlated with nadir GH levels during OGTT (p<0.001). GH was inversely related to age in both sexes (p<0.001). Diabetes mellitus was present in 27.5%, hypertension in 28.8%, sleep apnea syndrome in 25.5% and cardiac hypertrophy in 15.5%. Serious cardiovascular outcomes like stroke, heart failure and myocardial infarction were present in <5% at diagnosis. Erythrocyte levels were increased and correlated with IGF-1 values. Thyroid nodules were frequent (34.0%); 820 patients had colonoscopy at diagnosis and 13% had polyps. Osteoporosis was present at diagnosis in 12.3% and 0.6-4.4% had experienced a fracture. This study of >3100 patients is the largest international acromegaly database and shows clinically relevant trends in the characteristics of acromegaly at diagnosis. [less ▲]

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See detailNatural patches in Posidonia oceanica meadows: the seasonal biogeochemical pore water characteristics of two edge types
Abadie, A; Borges, Alberto ULg; Champenois, Willy ULg et al

in Marine Biology (2017), 164:166

Seagrass meadows can be assimilated to seascape matrixes encompassing a mosaic of natural and anthropogenic patches. Natural patches within the Mediterranean Posidonia oceanica meadows show a structural ... [more ▼]

Seagrass meadows can be assimilated to seascape matrixes encompassing a mosaic of natural and anthropogenic patches. Natural patches within the Mediterranean Posidonia oceanica meadows show a structural particularity which consist in a duality of their edge types. One edge is eroded by bottom currents, while the adjacent meadow colonizes the bare sediments. This study aims to study the dynamics of these two edges through the investigation of the biogeochemistry (pH, total alkalinity, dissolved inorganic carbon, CO2, CH4, N2O, H2S, dissolved inorganic nitrogen, PO4 3−) within vegetated and unvegetated sediments. These observations are compared with the adjacent meadow to have a better understanding of the colonization processes. Our results reveal that the P. oceanica matrix shows differences from the vegetated edges of sand patches, especially with regard to nutrient availability, which is generally more important at the colonized edge (dissolved inorganic nitrogen up to 65.39 μM in June). A clear disparity also occurs between the eroded and colonized edge with both a seasonal and bathymetrical variation of leaf biomass with higher disparities at 10 m in June (colonized edge 1415 gDW m−2; eroded edge 1133 gDW m−2). Themost important contrasts during this study were assessed in June, suggesting that the warm period of the year is more suitable for sampling to highlight disparate characteristics in temperate seagrass meadows. These findings put into light the potential importance of biogeochemical processes in the dynamics of natural patch edges. We hypothesize that they may influence the structural dynamics of P. oceanica seascapes. [less ▲]

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See detailEffects of User IT Capabilities and Organized Big Data Analytics on Competitive Advantage
Kamioka, Taro; Hosoya, Ryuichi; Tapanainen, Tommi ULg

in Proceedings of the Pacific-Asian Conference on Information Systems (PACIS) (2017, July 20)

In the age of big data, it becomes important to develop capabilities for utilizing information technology (IT) in order to take advantage of the potential of data for business objectives. While users have ... [more ▼]

In the age of big data, it becomes important to develop capabilities for utilizing information technology (IT) in order to take advantage of the potential of data for business objectives. While users have received attention in many ways, we note that the capability literature has focused more on the IT supply side. We argue that user capabilities have moved to an integral position in firm competitive advantage, and call them “User IT Capabilities” (UIC). A survey was conducted to collect data from Japanese organizations, and a total valid sample of 1,170 respondents involved in big data use was extracted. The findings show the effect of UIC on the performance of big data analytics and firm competitiveness, mediated by the variable of organized big data analytics (OBDA). The direct effects are shown to be valid irrespective of company size, although the levels of UIC and OBDA are higher in larger firms. [less ▲]

Detailed reference viewed: 47 (4 ULg)