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See detailInvestigating missing sources of formic acid
Franco, Bruno ULg; Taraborrelli, Domenico; Schultz, Martin G.

Scientific conference (2016, September 28)

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See detailINVESTIGATING MODEL DEFICIENCIES IN THE GLOBAL BUDGET OF ETHANE
Tzompa-Sosa, Z. A.; Keller, C. A.; Turner, A. J. et al

Poster (2015, December 14)

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See detailInvestigating non-coding viral transcripts in Bovine Leukemia Virus induced leukemia
Hahaut, Vincent ULg; Artesi, Maria ULg; Durkin, Keith ULg et al

Poster (2017, March 08)

Bovine Leukemia Virus (BLV) is a deltaretrovirus closely related to the Human T-cell leukemia virus-1 (HTLV-1). The natural host of BLV is cattle and much like the case of HTLV-1 in humans, about ~5% of ... [more ▼]

Bovine Leukemia Virus (BLV) is a deltaretrovirus closely related to the Human T-cell leukemia virus-1 (HTLV-1). The natural host of BLV is cattle and much like the case of HTLV-1 in humans, about ~5% of infected individuals develop leukemia/lymphoma following a long period of asymptomatic infection (~7 years in cattle, several decades in human). Experimental infection of sheep with BLV results in a reduced latency period (2 years on average), making for an attractive cancer model. A further advantage of the BLV system is that it is possible to infect sheep via injection of a cloned provirus, facilitating the mutation of specific parts of the viral genome to examine the function of viral products in vivo. Like HTLV-1, the BLV mRNAs/proteins are transcribed from the viral 5’ long terminal repeat (LTR), a region rich in regulatory elements. It was previously believed that the BLV provirus was transcriptionally silent in tumors, however we identified a cluster of five abundantly expressed non-canonical RNA polymerase III dependent microRNAs (miRNAs) encoded by BLV (Rosewick et al., PNAS 2013). In addition, using RNA sequencing we recently discovered viral antisense transcripts originating in the 3' Long Terminal Repeat (LTR) of the BLV provirus (Durkin et al., Retrovirology 2016) . While 5'LTR dependent transcription is absent in malignant cells, both the viral miRNAs and the antisense transcripts are expressed in all BLV induced leukemic and pre-leukemic samples examined to date, pointing to a vital role in the life cycle of the virus and a critical function in cellular transformation. [less ▲]

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See detailInvestigating Prostaglandin E2 activation of the p38 pathway of oesophageal squamous cell carcinoma
Rambout, Xavier ULg

Master's dissertation (2008)

Background, aim and objectives: Oesophageal squamous cell carcinoma (OSCC) is an endemic disease. Epidemiologic studies driven by investigation of Sammon in a region with one of the highest prevalence ... [more ▼]

Background, aim and objectives: Oesophageal squamous cell carcinoma (OSCC) is an endemic disease. Epidemiologic studies driven by investigation of Sammon in a region with one of the highest prevalence, linked a predisposition to develop OSCC to a high consumption of maize via reflux disease and chronic oesophagitis. In that context, it was postulated that prostaglandin E2 (PGE2), a hormone derived from a main component of maize, continuously triggers activation of proliferation and inflammation pathways. This work aimed at assessing the role of p38, a mitogen-activated protein kinase (MAPK), in the potential of PGE2 to trigger cellular proliferation, transcription and expression of proliferative (Cyclin D1) and inflammatory (IL-6) mediators in a human epithelial oesophageal cell line (Het1a). Methods: The proliferation potential of PGE2 via p38 was assessed by MTT assay on Het1a. The effect of H2O2 treatments was also assessed as a positive control. Then, RNA and protein samples were extracted from that cell line previously PGE2-treated. Transcription and expression profiles were studied over time respectively by quantitative polymerase chain reaction (qPCR) and western blot. The role of p38 was assessed by addition of a specific inhibitor, SB203580, to the cells under investigation. Results and Discussion: It was shown that PGE2 alone could not trigger proliferation of the Het1a cell line. Though, the effect of p38 might be positive. Acute H2O2 treatments turned out encouraging in the development of a model of p38 activation. Regulation of Cyclin D1 and IL-6 transcription was suggested to occur through PGE2 and via the p38 pathway. The Cyclin D1 and IL-6 transcripts were respectively overexpressed and downregulated in a bimodal manner, the second peak relying exclusively on p38 activation. Both observations could be supported by a positive feedback theory involving cyclooxygenase (COX)-2. Conclusions: Even though PGE2 was shown not to be sufficient to promote Het1a proliferation, regulation of Cyclin D1 and IL-6 transcription via p38 was observed. Furthermore, the expression profile might support the Sammon-Pink theory. [less ▲]

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See detailInvestigating relationships between Landsat ETM+ data and LAI in a semi-arid grassland of northwest China
Lu, L; Li, X; Ma, M G et al

in Geoscience and Remote Sensing Symposium, 2004. Proceedings IGARSS '04. (2004)

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See detailInvestigating resting-state functional connectivity in the cervical spinal cord at 3T.
Eippert, Falk; Kong, Yazhuo; Winkler, Anderson ULg et al

in NeuroImage (2017), 147

The study of spontaneous fluctuations in the blood-oxygen-level-dependent (BOLD) signal has recently been extended from the brain to the spinal cord. Two ultra-high field functional magnetic resonance ... [more ▼]

The study of spontaneous fluctuations in the blood-oxygen-level-dependent (BOLD) signal has recently been extended from the brain to the spinal cord. Two ultra-high field functional magnetic resonance imaging (fMRI) studies in humans have provided evidence for reproducible resting-state connectivity between the dorsal horns as well as between the ventral horns, and a study in non-human primates has shown that these resting-state signals are impacted by spinal cord injury. As these studies were carried out at ultra-high field strengths using region-of-interest (ROI) based analyses, we investigated whether such resting-state signals could also be observed at the clinically more prevalent field strength of 3T. In a reanalysis of a sample of 20 healthy human participants who underwent a resting-state fMRI acquisition of the cervical spinal cord, we were able to observe significant dorsal horn connectivity as well as ventral horn connectivity, but no consistent effects for connectivity between dorsal and ventral horns, thus replicating the human 7T results. These effects were not only observable when averaging along the acquired length of the spinal cord, but also when we examined each of the acquired spinal segments separately, which showed similar patterns of connectivity. Finally, we investigated the robustness of these resting-state signals against variations in the analysis pipeline by varying the type of ROI creation, temporal filtering, nuisance regression and connectivity metric. We observed that - apart from the effects of band-pass filtering - ventral horn connectivity showed excellent robustness, whereas dorsal horn connectivity showed moderate robustness. Together, our results provide evidence that spinal cord resting-state connectivity is a robust and spatially consistent phenomenon that could be a valuable tool for investigating the effects of pathology, disease progression, and treatment response in neurological conditions with a spinal component, such as spinal cord injury. [less ▲]

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See detailInvestigating rock-slope failures in the Tien Shan: State-of-the-art and perspectives of international cooperation (M111).
Strom, A.; Korup, O.; Abdrakhmatov, K. et al

Scientific conference (2005)

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See detailInvestigating State Reconstruction from Scarce Synchronized Phasor Measurements
Glavic, Mevludin; Van Cutsem, Thierry ULg

in Proceedings of the IEEE Trondheim Power Tech 2011 conference (2011, June)

Synchronized phasor measurements can potentially track the system dynamics between two classical state estimations. However, in the PMU configurations available nowadays and in the near future, those ... [more ▼]

Synchronized phasor measurements can potentially track the system dynamics between two classical state estimations. However, in the PMU configurations available nowadays and in the near future, those measurements are too scarce for the whole system state to be estimated. Therefore, we investigate the possibility to reconstruct coherent, time-synchronized system states from the available PMU data. State reconstruction is formulated as an optimization problem. The objective is to minimize, in the space of bus powers, the distance between the reconstructed state and the last state estimate provided by a standard state estimator. PMU data are imposed as equality constraints. Furthermore, the placement of PMUs near generators is advocated for higher accuracy of state reconstruction. The performance and potential benefits of the approach are illustrated by processing snapshots obtained from detailed time simulation of a test system subject to a disturbance and corrective actions. [less ▲]

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See detailInvestigating the effect of blind hole pinning on the magnetization response of a superconductor
Shaw, Gorky ULg; Mohan, Shyam; Sinha, Jaivardhan et al

Poster (2008)

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See detailInvestigating the effect of blind hole pinning on the magnetization response of a superconductor.
Shaw, Gorky ULg; Mohan, Shyam; Sinha, Jaivardhan et al

Poster (2010, February)

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See detailInvestigating the Effect of Plant Root Exudates and of Saponin on Polycyclic Aromatic Hydrocarbons Solubilization in Brownfield Contaminated Soils
Davin, Marie ULg; Fauconnier, Marie-Laure ULg; Colinet, Gilles ULg

Conference (2016, August 08)

In Wallonia, there are 6,000 estimated brownfields (rising to over 3.5 million in Europe) that require remediation. Polycyclic Aromatic Hydrocarbons (PAHs) are a class of recalcitrant carcinogenic ... [more ▼]

In Wallonia, there are 6,000 estimated brownfields (rising to over 3.5 million in Europe) that require remediation. Polycyclic Aromatic Hydrocarbons (PAHs) are a class of recalcitrant carcinogenic/mutagenic organic compounds of major concern as they accumulate in the environment and represent 17% of all encountered pollutants. As an alternative to environmentally aggressive, expensive and often disruptive soil remediation strategies, a lot of research has been directed to developing techniques targeting organic pollutants. The following experiment, based on the observation that PAHs soil content decreases in the presence of plants, aimed at improving our understanding of the underlying mechanisms involved in phytoremediation. It focusses on plant root exudates and whether they improve PAHs solubilization, which would make them more available for bioremediation by soil microorganisms. The effect of saponin, a natural surfactant found in some plant roots such as members of the Fabaceae family, on PAHs solubilization was also investigated as part of the implementation of the experimental protocol. The experiments were conducted on soil collected from a brownfield in Saint-Ghislain (Belgium) and presenting weathered PAHs contamination. Samples of soil were extracted with different solutions containing either plant root exudates or commercial saponin. Extracted PAHs were determined in the different aqueous solutions using High-Performance Liquid Chromatography and Fluorimetric Detection (HPLC-FLD). Both root exudates of alfalfa (Medicago sativa L.) or red clover (Trifoliumpratense L.) and commercial saponin were tested in different concentrations. Distilled water was used as a control. First of all, results show that PAHs are more extracted using saponin solutions than distilled water and that the amounts generally rise with the saponin concentration. However, the amount of each extracted compound diminishes as its molecular weight rises. Also, it appears that passed a certain surfactant concentration, PAHs are less extracted. This suggests that saponin might be investigated as a washing agent in polluted soil remediation techniques, either for ex situ or in situ treatments, as an alternative to synthetic surfactants. On the other hand, preliminary results on experiments using plant root exudates also show differences in PAHs solubilization compared to the control solution. Further results will allow discussion as to whether or not there are differences according to the exudates provenance and concentrations. [less ▲]

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See detailInvestigating the effect of plant-derived amendments on PAHs degradation in brownfield contaminated soils
Davin, Marie ULg; Starren, Amandine ULg; Colinet, Gilles ULg et al

Conference (2016, September 13)

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistant organic compounds of major concern that tend to accumulate in the environment, damaging ecosystems and health. Brownfields represent an ... [more ▼]

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistant organic compounds of major concern that tend to accumulate in the environment, damaging ecosystems and health. Brownfields represent an important tank for PAHs that require remediation. As an alternative to environmentally aggressive, expensive and often disruptive soil remediation strategies, experiences have been carried on to understand and develop techniques based on bioremediation and phytoremediation. PAHs degradation experiments were conducted in microcosms (laboratory scale) in order to determine whether several plant-derived amendments could enhance bioremediation. Briefly, samples of aged contaminated soils were treated with different concentrations of Medicago sativa or Trifolium pratense root exudates or dried roots, commercial saponin, a natural surfactant found in some plant roots such as some Fabaceae, and some samples were left unamended as controls. Soil samples were incubated for two and four weeks at controlled temperature (28°C). Carbon dioxide emission was monitored throughout the whole incubation. At the end of each experiment, dehydrogenase activity was measured as an indicator of microbiological activity and residual PAHs were determined using High-Performance Liquid Chromatography with Fluorimetric Detection (HPLC-FLD). In total, eleven amendment modalities and two incubation periods were tested and repeated four times. Preliminary experiments show promising results as amended samples seem to show different respiration activities. Ongoing studies will allow discussion as to whether or not PAHs degradation is influenced by the different modalities and if there are any differences according to the nature and concentration of the amendment. [less ▲]

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See detailInvestigating the effects of hydrodynamics and mixing on mass transfer through the free-surface in stirred tank bioreactors
de Lamotte, Anne ULg; Delafosse, Angélique ULg; Calvo, Sébastien ULg et al

in Chemical Engineering Science (2017), 172

In stirred-tank bioreactors, flow structures of various length and time scales are implied in scalar transport phenomena, such as gas species transfer through the liquid free-surface and their ... [more ▼]

In stirred-tank bioreactors, flow structures of various length and time scales are implied in scalar transport phenomena, such as gas species transfer through the liquid free-surface and their homogenization in the bulk. A proper understanding of the underlying mechanisms, i.e. hydrodynamics, mixing and mass transfer, and of their interactions is required to design and develop reliable and efficient production-scale bioprocesses. The objective of the present work is to experimentally investigate the coupling between gas-liquid mass transfer of oxygen with mixing efficiency and circulation patterns inside an arbitrarily chosen stirred-tank configuration aerated through the liquid free-surface, a baffled 20 L-vessel agitated by two Rushton turbines. Based on global parameter values, the most appropriate rotating speed, N = 300 rpm, is selected in order to further study local hydrodynamic quantities using Particle Image Velocimetry (PIV), as well as mixing and mass transfer dynamics using Planar Laser-Induced Fluorescence (PLIF). The results obtained with these local experimental methods are analyzed in detail. Their averages are first successfully compared to global data. Statistical analysis of their spatial distributions show that large-scale flow patterns significantly influence mass transfer through the free-surface of the stirred tank. Even if global measurements show that global characteristic times for mixing and mass transfer differ by two orders of magnitude, local experimental characterization shows persistent vertical gradients of dissolved gas concentrations. So the dissolved gas concentration is not as perfectly uniform as one might expect. [less ▲]

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See detailInvestigating the Effects of Plant Root Exudates on PAHs Bioavailability to Soil Microorganisms in Contaminated Brownfields : Research Methodology.
Davin, Marie ULg; Lognay, Georges ULg; Fauconnier, Marie-Laure ULg et al

Poster (2015, January 30)

As a result of heavy industrial past activities, an estimated 6,000 brownfields require remediation in Wallonia. This number rises to over 3.5 million in Europe. Polycyclic Aromatic Hydrocarbons (PAHs ... [more ▼]

As a result of heavy industrial past activities, an estimated 6,000 brownfields require remediation in Wallonia. This number rises to over 3.5 million in Europe. Polycyclic Aromatic Hydrocarbons (PAHs) represent 17% of treated pollutants in Wallonia (Aldric et al., 2011). Current remediation techniques are rather expensive and technically demanding (Megharaj et al., 2011). Based on the observation that PAHs soil content decreases in the presence of plants (Cheema et al., 2010), the PhD aims at developing alternative PAHs remediation techniques in brownfields. It is articulated around three research axes. The first axis focusses on plant exudates and how they may improve PAHs bioavailability to soil microorganisms and enhance their degradation. This will be investigated by (i) characterizing several contaminated soils (physico-chemical parameters) and PAH content and factors of bioavailability, (ii) selecting a plant model and collecting root exudates, and (iii) evaluating the effects of exudates on PAHs bioavailability. The objective of the second axis is to evaluate the effects of plant exudates on PAHs degrading microorganisms by (i) comparing PAHs biodegradation in the presence/absence of exudates and (ii) assessing the potential toxic effects of exudate compounds on the microbial communities. The aim of the third axis is to study plant-pollutants interactions by (i) establishing the plant tolerance to several contamination levels and (ii) following PAHs bioavailability when facing real exudation rates, on the field. [less ▲]

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See detailInvestigating the Effects of Training and Techno-Pedagogical Support
Lecomte, Béatrice ULg; Van de Poël, Jean-François ULg; Verpoorten, Dominique ULg et al

Conference (2013, December)

This communication presents a quantitative-qualitative research conducted among 225 teachers and teaching assistants who have benefited from the education technologies training program provided by our ... [more ▼]

This communication presents a quantitative-qualitative research conducted among 225 teachers and teaching assistants who have benefited from the education technologies training program provided by our eCampus department at IFRES (University of Liege, Belgium) since 2011. The data collected are used to a) describe and characterize the public who attended these training sessions, b) identify the types of training programs chosen by the attendees, and c) to explore the influence of those sessions on the techno-pedagogical development of teachers. That effect is manifested by a change of mental representations or by "acting out" in terms of integrating technology into teaching practices. [less ▲]

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See detailInvestigating the factors for fermentative biohydrogen improvement: original bioreactors design and hydrogen partial pressure effect
Beckers, Laurent ULg; Hiligsmann, Serge ULg; Hamilton, Christopher ULg et al

in WHEC 2012, Toronto June 3rd - 7th (2012, June 05)

The anaerobic production of hydrogen from biomass offers the potential production of usable biogas from a variety of renewable resources. However, in order to produce hydrogen at high yields and ... [more ▼]

The anaerobic production of hydrogen from biomass offers the potential production of usable biogas from a variety of renewable resources. However, in order to produce hydrogen at high yields and production rates the biotechnological process needs to be further optimized and efficient bioreactors must be designed [1]. At the CWBI, a continuous horizontal rotating cylinder bioreactor has been designed and investigated to produce biohydrogen from glucose by the strain Clostridium butyricum [2] at good yields (1,9molH2•molglucose-1) and production rates (48,6mmolH2•Lmilieu-1.molhexose-1•h-1). This reactor has an internal volume of 2.3L and a small working volume (300ml) (fig.1). It enhances the hydrogen production rates (by about three times more than a completely stirred bioreactor) by partially immobilizing the bacteria on the porous support. Moreover, the rotating cylinder design enables efficient H2 gas transfer from the liquid phase increasing hydrogen yields by about 25% compared to a completely stirred bioreactor [3-4]. Other original bioreactors, such as a trickle bed, have been built with the same aim of lowering the hydrogen partial pressure and led to similar results. Our work shows the importance of a good liquid to gas transfers in the biohydrogen-producing reactors to reach higher performances. [less ▲]

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See detailInvestigating the Impact of Different Thermal Comfort Models for Zero Energy Buildings in Hot Climates
Attia, Shady ULg; Hensen, JLM

in Proceedings 1st Int. Conf. on Energy and Indoor Environment for Hot Climates (2014, February 24)

The selection of a thermal comfort model has a major impact on energy consumption of Net Zero Energy Buildings (NZEBs) in hot climates. The objective of this paper is to compare the influence of using ... [more ▼]

The selection of a thermal comfort model has a major impact on energy consumption of Net Zero Energy Buildings (NZEBs) in hot climates. The objective of this paper is to compare the influence of using different comfort models for zero energy buildings in hot climates. The paper compares the impact of applying Givoni’s model, ASHRAE 55 adaptive comfort standard, EN 15251 adaptive comfort standard and EN ISO 7730 on energy consumption and comfort. Using ZEBO and EnergyPlus for energy simulation, an existing prototype of a residential apartment module will be used to evaluate energy performance and thermal comfort in two parametric series. The first one is the result of coupling natural ventilation and mechanical cooling and the second one is guided coupling natural ventilation, mechanical cooling and ceiling fans. Results show a significant difference of cooling loads and total energy generation for the compared comfort models. However, the study remains theoretical and requires post occupancy evaluation for a better reliability of the results. [less ▲]

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See detailInvestigating the intraspecific biodiversity of the threatened rodent Leopoldamys neilli in Southeast Asia
Latinne, Alice ULg; Waengsothorn, Surachit; Herbreteau, Vincent et al

Conference (2010, September 23)

We study the phylogeography of Leopoldamys neilli, a threatened murine rodent species endemic to limestone karsts of Thailand, in order to assess the influence of its endemicity to karstic habitat on its ... [more ▼]

We study the phylogeography of Leopoldamys neilli, a threatened murine rodent species endemic to limestone karsts of Thailand, in order to assess the influence of its endemicity to karstic habitat on its intraspecific biodiversity and phylogeographic pattern. Samples of L. neilli were collected in limestone karsts from 20 localities in seven provinces of Thailand. Two mitochondrial markers, the cytochrome b gene (cytb) and the cytochrome c oxydase subunit I gene (COI), were sequenced for 115 L. neilli individuals. A nuclear fragment, the β-fibrinogen intron 7 (bfibr), was amplified in a subset of 65 samples. Phylogenetic reconstructions and median joining networks were used to explore relationships between haplotypes of the studied populations. Haplotype and nucleotide diversities of the main lineages were estimated for each locus. Divergence times of the main lineages of L. neilli were estimated using Bayesian inference. The demographic histories of the main lineages of L.neilli were also examined. Our study gave evidence of a strong geographic structure of the genetic diversity for L. neilli. Six highly differentiated genetic lineages were observed in the phylogenetic and phylogeographic analyses. These lineages are allopatric and correspond to particular regions of Thailand. They exhibit very high degree of genetic divergence and gene flows between them are extremely low. Within each lineage, the levels of haplotype and nucleotide diversities are very low for each gene. These results suggest a severe fragmentation of L. neilli’s populations, correlated to the fragmented distribution of its habitat and highlight its high endemicity to limestone karsts. The strong phylogeographic pattern of L. neilli and the very ancient separation of some lineages could be explained by the geological history of Thailand during Tertiary and Quaternary era. In conclusion, this study revealed an unexpectedly high level of intraspecific biodiversity within the species L. neilli. These results consolidate the importance to strengthen the protection of limestone habitats and to preserve not only their huge interspecific but also intraspecific biodiversity. [less ▲]

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