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See detailA Comparison between four Techniques to Measure Cardiac Output
Pironet, Antoine ULg; Dauby, Pierre ULg; Chase, J. Geoffrey et al

in Proceedings of the 38th International Conference of the IEEE Engineering in Medicine and Biology Society (2016, August 17)

Cardiac output is an important variable when monitoring hemodynamic status. In particular, changes in cardiac output represent the goal of several circulatory management therapies. Unfortunately, cardiac ... [more ▼]

Cardiac output is an important variable when monitoring hemodynamic status. In particular, changes in cardiac output represent the goal of several circulatory management therapies. Unfortunately, cardiac output is very difficult to estimate, either in experimental or clinical settings. The goal of this work is to compare four techniques to measure cardiac output: pressure-volume catheter, aortic flow probe, thermodilution, and the PiCCO monitor. These four techniques were simultaneously used during experiments of fluid and endotoxin administration on 7 pigs. Findings show that, first, each individual technique is precise, with a relative coefficient of repeatability lower than 7 %. Second, 1 cardiac output estimate provided by any technique relates poorly to the estimates from the other 3, even if there is only small bias between the techniques. Third, changes in cardiac output detected by one technique are only detected by the others in 62 to 100 % of cases. This study confirms the difficulty of obtaining a reliable clinical cardiac output measurement. Therefore, several measurements using different techniques should be performed, if possible, and all such should be treated with caution. [less ▲]

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See detailÉmotion, ipséité, liberté. Réflexions à propos des fondements de la théorie sartrienne des émotions
Recchia, Fabio ULg

in Bulletin d'Analyse Phénoménologique (2016), 12(5), 1-23

Entretenue durant la drôle de guerre, la correspondance épistolaire entre De Beauvoir et Sartre révèle une insatisfaction de ce dernier à l'égard de sa théorie des émotions. Celle-ci manquerait en effet ... [more ▼]

Entretenue durant la drôle de guerre, la correspondance épistolaire entre De Beauvoir et Sartre révèle une insatisfaction de ce dernier à l'égard de sa théorie des émotions. Celle-ci manquerait en effet de fondements solides. Répondant à ce constat, nous tenterons de dégager les fondations de cette théorie de manière à expliciter ses enjeux. Nous replacerons, pour ce faire, l'Esquisse d'une théorie des émotions dans la perspective plus générale de la théorie de l'intentionnalité du premier Sartre. De la sorte nous montrerons, d'une part, comment ce texte renouvelle significativement la catégorie de l'action en concevant l'émotion comme une activité ; et nous examinerons, d'autre part, l'interaction existant entre l¿émotion et l'ipséité de la conscience. Cette discussion dévoilera ainsi l'intentionnalité émotive comme une passion active reconduisant au fondement de la conscience qui est sa liberté personnelle. [less ▲]

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See detailReformulations of nonlinear binary optimization problems
Crama, Yves ULg

Scientific conference (2016, August 17)

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See detailThe Chemistry of New Garlic-Derived Organosulfur Compounds and the Molecular Basis of Olfaction »
Dethier, Bérénice ULg

Doctoral thesis (2016)

Garlic is a very popular condiment that has been used around the world for centuries. It is also a source of a remarkably extensive range of organosulfur compounds, whose chemistry is the focus of this ... [more ▼]

Garlic is a very popular condiment that has been used around the world for centuries. It is also a source of a remarkably extensive range of organosulfur compounds, whose chemistry is the focus of this thesis. The central reaction in formation of these compounds is the enzymatic cleavage of alk(en)yl cysteine sulfoxides by alliinases, which leads to sulfenic acids. The latter can then undergo condensation and rearrangement into various organosulfur compounds. Three aspects of the chemistry of garlic have been investigated in this thesis. First, little studied, minor organosulfur compounds in extracts of freshly chopped garlic were studied. These higher molecular weight compounds (MW 150–550) can be conveniently studied using state-of-the-art Liquid Chromatography-Mass Spectrometry (LC-MS) and Direct Analysis in Real Time-Mass Spectrometry (DART-MS) techniques. Novel garlic-derived compounds were studied and the structure of one representative compound containing a five-membered thiolane ring, ajothiolane, was determined by spectroscopic methods, using synthetic analogues as spectroscopic standards. The fate of compounds in a garlic extract over time was also studied, since the new, higher mass sulfur compounds are slowly formed by rearrangement of smaller metabolites a few days after maceration of the garlic. A second part of this thesis provides hands-on methods for the analysis and preparation of key garlic metabolites. The isolation and/or synthesis of alliin, alliinase and vinyldithiins have been optimized, and are proposed as turnkey procedures for future work. Finally, in an effort to explain the unique odor of garlic-related thiols and sulfides (in garlic breath, sweat, etc.), the interactions between odorants and olfactory receptors have been studied. Work described in this thesis contributed to this larger project by designing and synthesizing model macrocyclic odorants to resolve the mechanism of olfaction at the receptor level. The conclusions, arguing against the plausibility of the so-called “vibration theory of olfaction”, have been published as a foundation for future work on olfactory detection of thiols and other sulfur-containing compounds. [less ▲]

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See detailUse of slow-release plant infochemicals to control aphids: a first investigation in a Belgian wheat field
Zhou, Haibo; Chen, Longsheng; Liu, Yong et al

in Scientific Reports (2016)

Using infochemicals to develop a push–pull strategy in pest control is a potential way to promote sustainable crop production. Infochemicals from plant essential oils were mixed with paraffin oil for slow ... [more ▼]

Using infochemicals to develop a push–pull strategy in pest control is a potential way to promote sustainable crop production. Infochemicals from plant essential oils were mixed with paraffin oil for slow release in field experiments on wheat to control the population density of cereal aphids and to enhance their natural enemies. (Z)-3-Hexenol (Z3H) attracted Metopolophum dirhodum and Sitobion avenae, the predominant species on wheat in Belgium, and may be a useful infochemical for aphid control by attracting aphids away from field plots. Release of (E)-β-farnesene (EBF) or a garlic extract (GE) led to a significant decrease in the abundance of wheat aphids. The main natural enemies of cereal aphids found were lacewings (47.8%), hoverflies (39.4%), and ladybirds (12.8%). Ladybird abundance varied little before the end of the wheat-growing season. Our results suggest that these chemicals can form the basis of a “push–pull” strategy for aphid biological control, with GE and EBF acting as a pestand beneficial-pulling stimulus and Z3H for aphid pulling. [less ▲]

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See detailCASTLE4D : The castle of Franchimont
Luczfalvy Jancsó, Andrea ULg; Hoffsummer, Patrick ULg; Billen, Roland ULg et al

Poster (2016, August 16)

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See detailHuman herpesvirus 8-encoded chemokine vCCL2/vMIP-II is an agonist of the atypical chemokine receptor ACKR3/CXCR7
Szpakowska, Martyna; Dupuis, Nadine ULg; Baragli, Alessandra et al

in Biochemical Pharmacology (2016), 114

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See detailA new global interior ocean mapped climatology: the 1° × 1° GLODAP version 2
Lauvset, Siv K.; Key, Robert M.; Olsen, Are et al

in Earth System Science Data (2016)

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See detailBackground subtraction and background generation
Van Droogenbroeck, Marc ULg

Conference (2016, August 15)

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See detailUlcerative pododermatitis and disseminated erosive lesions associated with cowpox virus infection in a domestic cat
Ludwig, Louisa ULg; Bohn, Jéromine ULg; Remy, Isabelle ULg et al

in Veterinary Record Case Reports (2016)

The authors report on a case of feline cowpox virus infection associated with severe ulcerative dermatitis of a paw and disseminated erosive lesions. While the anamnesis of the cat being a known rodent ... [more ▼]

The authors report on a case of feline cowpox virus infection associated with severe ulcerative dermatitis of a paw and disseminated erosive lesions. While the anamnesis of the cat being a known rodent-hunter, a typical seasonality of infection and the progression of clinical signs from a primary anterior lesion (forelimb) indicated a possible cowpox virus infection, the differential diagnosis was complicated by the resemblance of clinical signs to those induced by feline herpesvirus-dermatitis or feline calicivirus infection. These differential diagnoses were excluded by means of immunostaining and PCR, respectively. Detection of eosinophilic intracytoplasmic inclusion bodies in cells from biopsy material and positive PCR and sequencing results confirmed the diagnosis of cowpox virus infection. Genetic characterisation of the isolate, based on the highly diverse haemagglutinin gene, showed that the strain (Liege 2015; GenBank accession number: KU726584) clustered with other European isolates, mostly from exotic zoo animals. [less ▲]

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See detailCharacterization of stony soils' hydraulic conductivity using laboratory and numerical experiments
Beckers, Eléonore ULg; Pichault, Mathieu; Pansak, Wanwisa et al

in SOIL (2016), 2

Determining soil hydraulic properties is of major concern in various fields of study. Although stony soils are widespread across the globe, most studies deal with gravel-free soils, so that the literature ... [more ▼]

Determining soil hydraulic properties is of major concern in various fields of study. Although stony soils are widespread across the globe, most studies deal with gravel-free soils, so that the literature describing the impact of stones on the hydraulic conductivity of a soil is still rather scarce. Most frequently, models characterizing the saturated hydraulic conductivity of stony soils assume that the only effect of rock fragments is to reduce the volume available for water flow, and therefore they predict a decrease in hydraulic conductivity with an increasing stoniness. The objective of this study is to assess the effect of rock fragments on the saturated and unsaturated hydraulic conductivity. This was done by means of laboratory experiments and numerical simulations involving different amounts and types of coarse fragments. We compared our results with values predicted by the aforementioned predictive models. Our study suggests that it might be ill-founded to consider that stones only reduce the volume available for water flow. We pointed out several factors of the saturated hydraulic conductivity of stony soils that are not considered by these models. On the one hand, the shape and the size of inclusions may substantially affect the hydraulic conductivity. On the other hand, laboratory experiments show that an increasing stone content can counteract and even overcome the effect of a reduced volume in some cases: we observed an increase in saturated hydraulic conductivity with volume of inclusions. These differences are mainly important near to saturation. However, comparison of results from predictive models and our experiments in unsaturated conditions shows that models and data agree on a decrease in hydraulic conductivity with stone content, even though the experimental conditions did not allow testing for stone contents higher than 20 %. [less ▲]

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See detailFunctional analysis of protein tyrosine phosphatases in thrombosis and haemostasis
Rahmouni, Souad ULg; Hego, Alexandre ULg; Delierneux, Céline ULg et al

in Protein Tyrosine Phosphatases: Methods and Protocols (2016)

Platelets are small blood cells derived from cytoplasmic fragments of megakaryocytes and play an essential role in thrombosis and haemostasis. Platelet activation depends on the rapid phosphorylation and ... [more ▼]

Platelets are small blood cells derived from cytoplasmic fragments of megakaryocytes and play an essential role in thrombosis and haemostasis. Platelet activation depends on the rapid phosphorylation and dephosphorylation of key signaling molecules, and a number of kinases and phosphatases have been identified as major regulators of platelet function. However, the investigation of novel signaling proteins has suffered from technical limitations due to the anucleate nature of platelets and their very limited levels of mRNA and de novo protein synthesis. In the past, experimental methods were restricted to the generation of genetically modified mice and the development of specific antibodies. More recently, novel (phospho)proteomic technologies and pharmacological approaches using specific small-molecule inhibitors have added additional capabilities to investigate specific platelet proteins. In this chapter, we report methods for using genetic and pharmacological approaches to investigate the function of platelet signaling proteins. While the described experiments focus on the role of the dual-specificity phosphatase 3 (DUSP3) in platelet signaling, the presented methods are applicable to any signaling enzyme. Specifically, we describe a testing strategy that includes 1) aggregation and secretion experiments with mouse and human platelets, 2) immunoprecipitation and immunoblot assays to study platelet signaling events, 3) detailed protocols to use selected animal models in order to investigate thrombosis and haemostasis in vivo, and 4) strategies for utilizing pharmacological inhibitors on human platelets. [less ▲]

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See detailFunctional analysis of dual-specificity protein phosphatases in angiogenesis
Amand, Mathieu; ERPICUM, Charlotte ULg; Gilles, Christine ULg et al

in Pulido, Rafael (Ed.) Protein Tyrosine Phosphatases: Methods and Protocols (2016)

Therapeutic perspectives targeting angiogenesis in cancer stimulated an intense investigation of the mechanisms triggering and governing angiogenic processes. Several publications have highlighted the ... [more ▼]

Therapeutic perspectives targeting angiogenesis in cancer stimulated an intense investigation of the mechanisms triggering and governing angiogenic processes. Several publications have highlighted the importance of typical dual-specificity phosphatases (DSPs) or MKPs in endothelial cells and their role in controlling different biological functions implicated in angiogenesis such as migration, proliferation, apoptosis, tubulogenesis and cell adhesion. However, among atypical DSPs, the only one investigated in angiogenesis was DUSP3. We recently identified this DSP as new key player in endothelial cells and angiogenesis. In this chapter we provide with detailed protocols and models used to investigate the role of DUSP3 in endothelial cells and angiogenesis. We start the chapter with an overview of the role of several DSPs in angiogenesis. We continue with providing a full description of a highly efficient transfection protocol to deplete DUSP3 using small interfering RNA (siRNA) in the primary Human Umbilical Vein Endothelial Cells (HUVEC). We next describe the major assays used to investigate different processes involved in angiogenesis such as tube formation assay, proliferation assay and spheroids sprouting assay. We finish the chapter by validating our results in DUSP3-knockout mice using in vivo angiogenesis assays such as Matrigel plug and Lewis lung carcinoma cell subcutaneous xenograft model followed by anti-CD31 immunofluorescence and ex vivo aortic ring assay. All methods described can be adapted to other phosphatases and signaling molecules. [less ▲]

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See detailAnnual Greenland accumulation rates (2009–2012) from airborne snow radar
Koenig, L.; Ivanoff, A.; Alexander, P. et al

in Cryosphere (The) (2016), 10

Contemporary climate warming over the Arctic is accelerating mass loss from the Greenland Ice Sheet through increasing surface melt, emphasizing the need to closely monitor its surface mass balance in ... [more ▼]

Contemporary climate warming over the Arctic is accelerating mass loss from the Greenland Ice Sheet through increasing surface melt, emphasizing the need to closely monitor its surface mass balance in order to improve sea-level rise predictions. Snow accumulation is the largest component of the ice sheet's surface mass balance, but in situ observations thereof are inherently sparse and models are difficult to evaluate at large scales. Here, we quantify recent Greenland accumulation rates using ultra-wideband (2–6.5 GHz) airborne snow radar data collected as part of NASA's Operation IceBridge between 2009 and 2012. We use a semiautomated method to trace the observed radiostratigraphy and then derive annual net accumulation rates for 2009–2012. The uncertainty in these radar-derived accumulation rates is on average 14 %. A comparison of the radar-derived accumulation rates and contemporaneous ice cores shows that snow radar captures both the annual and long-term mean accumulation rate accurately. A comparison with outputs from a regional climate model (MAR) shows that this model matches radar-derived accumulation rates in the ice sheet interior but produces higher values over southeastern Greenland. Our results demonstrate that snow radar can efficiently and accurately map patterns of snow accumulation across an ice sheet and that it is valuable for evaluating the accuracy of surface mass balance models. [less ▲]

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See detailHoney polyphenols extraction: method development and evidence of cis isomerization
Istasse, Thibaut ULg; Jacquet, Nicolas ULg; Berchem, Thomas ULg et al

in Analytical Chemistry Insights (2016), 11

Honey polyphenols have been studied with the objective of relating honeys to their floral sources. Initially synthesized by plant, these polyphenols can be found in the plant’s nectar, where they are ... [more ▼]

Honey polyphenols have been studied with the objective of relating honeys to their floral sources. Initially synthesized by plant, these polyphenols can be found in the plant’s nectar, where they are collected by bees which convert the nectar into honey. Consequently, polyphenols constitute minor honey components. The development of a solid phase extraction method for honey polyphenols is presented herein. The technique employs Amberlite XAD-2 adsorbent and was tested on monofloral honeys from six different plants: acacia, chestnut, eucalyptus, thyme, sunflower and wild carrot. Analyses were performed using high performance liquid chromatography coupled with UV detection and mass spectrometry. Several phenolic acids and flavonoids were identified: caffeic and p-coumaric acids, quercetin, kaempferol, naringenin, chrysin and pinocembrin. Generally, the quantity of a given polyphenol in the honey was around 0.2 mg/100g of honey, except for chestnut honey which contained around 3.0 mg of p-coumaric acid/100g of honey. Analyses highlighted significant formation of cis isomers for phenolic acids during the extraction despite protection from light. [less ▲]

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See detailEffectiveness of temporary implants in teenage patients: a prospective clinical trial
LAMBERT, France ULg; BOTILDE, Gaëlle ULg; LECLOUX, Geoffrey ULg et al

in Clinical Oral Implants Research (2016)

Abstract Aims: The objective of this study was to assess prospectively the outcomes of extra-narrow diameter implants (XNDI) placed in teenage patients as a temporary restorative option. Material and ... [more ▼]

Abstract Aims: The objective of this study was to assess prospectively the outcomes of extra-narrow diameter implants (XNDI) placed in teenage patients as a temporary restorative option. Material and Methods: Twenty consecutive young patients presenting one or several missing teeth received XNDI that were immediately restored with composite, Polymethylmethacrylate (Acrylic) or ceramic crown. Clinical and radiographical outcomes were assessed for a minimum follow-up period of 1 year. Additionally, each patient completed retrospectively a satisfaction questionnaire using Visual Analog Scale (VAS). Results: A total of 30 implants were placed and followed for a period of 1–7.4 years (mean: 3.59 years). One implant failed after 3 weeks and was replaced successfully. No further biological complications occurred during the follow-up period, leading to an implant survival rate of 96.6%. The patient satisfaction evaluations displayed high levels of comfort and function. Conclusion: Immediately restored XNDI to replace missing teeth on teenager patients seems to be an effective temporary restorative option to replace missing teeth in young patients. Composite or ceramic crowns should be preferred. Clinical trials with long-term follow-ups and the assessment of passive egression are needed. [less ▲]

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See detailTen years of atmospheric methane from ground-based NDACC FTIR observations
Bader, Whitney ULg; Bovy, Benoît ULg; Conway, S. et al

in Atmospheric Chemistry & Physics Discussions (2016), 2016

Changes of atmospheric methane (CH4) since 2005 have been evaluated using Fourier Transform Infrared (FTIR) solar observations performed at ten ground-based sites, all members of the Network for Detection ... [more ▼]

Changes of atmospheric methane (CH4) since 2005 have been evaluated using Fourier Transform Infrared (FTIR) solar observations performed at ten ground-based sites, all members of the Network for Detection of Atmospheric Composition Change (NDACC). From this, we find an increase of atmospheric methane total columns that amounts to 0.31 ± 0.03 % year-1 (2-sigma level of uncertainty) for the 2005–2014 period. Comparisons with in situ methane measurements at both local and global scales show good agreement. We used the GEOS-Chem Chemical Transport Model tagged simulation that accounts for the contribution of each emission source and one sink in the total methane, simulated over the 2005–2012 time period and based on emissions inventories and transport. After regridding according to NDACC vertical layering using a conservative regridding scheme and smoothing by convolving with respective FTIR seasonal averaging kernels, the GEOS-Chem simulation shows an increase of atmospheric methane of 0.35 ± 0.03 % year-1 between 2005 and 2012, which is in agreement with NDACC measurements over the same time period (0.30 ± 0.04 % year-1, averaged over ten stations). Analysis of the GEOS-Chem tagged simulation allows us to quantify the contribution of each tracer to the global methane change since 2005. We find that natural sources such as wetlands and biomass burning contribute to the inter-annual variability of methane. However, anthropogenic emissions such as coal mining, and gas and oil transport and exploration, which are mainly emitted in the Northern Hemisphere and act as secondary contributors to the global budget of methane, have played a major role in the increase of atmospheric methane observed since 2005. Based on the GEOS-Chem tagged simulation, we discuss possible cause(s) for the increase of methane since 2005, which is still unexplained. [less ▲]

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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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