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See detailLegitimating innovation by foreign traditions: the case of the Roman Republican divination
Berthelet, Yann ULiege

Conference (2017, September 20)

Detailed reference viewed: 22 (3 ULiège)
See detailLipin-1 regulates cancer cell phenotype and is a potential target to amplify the effect of metabolic inhibitors
Brohée, Laura ULiege

Doctoral thesis (2017)

An increased lipogenesis was reported in various cancers and its inhibition represses proliferation and induces apoptosis of cancer cells while barely affecting most normal cells. The family of lipins ... [more ▼]

An increased lipogenesis was reported in various cancers and its inhibition represses proliferation and induces apoptosis of cancer cells while barely affecting most normal cells. The family of lipins encompasses three members: lipin-1, -2 and -3. All exhibit dual functions as enzymes, catalyzing the de-phosphorylation of phosphatidic acid to diacylglycerol, and as co-transcriptional regulators. Thus, they are able to regulate lipid homeostasis at several nodal points. However, no studies addressed the involvement of these proteins in cancer progression neither in vitro nor in vivo. During this PhD work, we first investigated the importance of lipin-1 on prostate cancer cell phenotype. We showed that lipin-1 expression is increased in various cancer cell types both in vitro and in vivo in human prostate tumor samples. The specific inhibition of lipin-1 in prostate and breast cancer cells demonstrated its critical importance for cell proliferation and migration through deregulation of several intracellular signaling pathways. This study demonstrated for the first time that the targeting of lipin-1 is a potential new anti-cancer strategy that could be used alone or in combination with drugs like rapamycin. During the course of these investigations, we also observed a compensatory regulation between lipin-1 and lipin-2 preventing the complete inhibition of lipins enzymatic activity when using a siRNA approach. Therefore, we focused our interest on inhibiting all lipins through treatment with a pharmacological inhibitor, propranolol. This drug also induced a blockade of the late phases of autophagy, likely because the inhibition of all lipins decreases diacylglycerol synthesis, which is required for the maturation of autolysosomes. Autophagy is a pro-survival mechanism induced by several stresses or by anticancer agents. In the case of the glycolysis inhibitor 2DG, the induction of autophagy limits its anticancer effects in monotherapy. In the light of their individual specific effects on cancer cells, we hypothesized that the combination of propranolol and 2DG might exert a more than additive toxic effect on cancer cells. In this second study, we report that combined treatment is effective on preventing prostate cancer cell proliferation, inducing cell apoptosis, altering the function of several organelles as mitochondria, endoplasmic reticulum and Golgi apparatus in vitro but also in suppressing tumor growth in vivo. Altogether, our data suggest that lipins are key players involved in cancer progression. Targeting lipins, alone or in combination with other treatments, could open new avenues in anticancer therapy. [less ▲]

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See detailWP1 - A summary
Sanchez, Christelle ULiege

Conference (2017, September 20)

Detailed reference viewed: 13 (1 ULiège)
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See detailLéon Graulich (1887-1966)
Desseilles, François ULiege

Scientific conference (2017, September 20)

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See detailPhenotyping hygienic behavior and studying diversity in honey bees (Apis mellifera L.): methodological issues and solutions
Leclercq, Gil ULiege

Doctoral thesis (2017)

Honey bees (Apis mellifera L.) are a crucial resource for world agriculture. The global stock of honey bees has increased over the last five decades. In contrast, honey bees have been declining in several ... [more ▼]

Honey bees (Apis mellifera L.) are a crucial resource for world agriculture. The global stock of honey bees has increased over the last five decades. In contrast, honey bees have been declining in several regions, especially in the northern hemisphere. Among the factors responsible for these regional declines, the parasitic mite Varroa destructor plays a central role and is considered as one of the main threats for apiculture. A sustainable solution to the problems caused by V. destructor is to breed Varroa-resistant honey bees. In this context, in Belgium, a research project was developed with the aim of studying the diversity of honey bees in Wallonia, and selecting, within this “local” diversity, Varroa-resistant honey bees. This project required methods to accurately phenotype Varroa-resistance traits, and methods to study the diversity of honey bee populations. In this thesis, we decided to work on these methods, which are a prerequisite for such research project. Two independent objectives were developed: (1) solving the controversy and methodological issues regarding the quantification of hygienic behavior in honey bee colonies, and (2) designing a new method to study the diversity of honey bee admixed populations covering a large-scale area, using pool-based sequencing data. The hygienic behavior of worker bees contributes to the social immunity of honey bee colonies. The manifestation of this behavior consists in detecting and removing unhealthy or dead brood. In this thesis, we reviewed the drawbacks, the benefits, and the methods to test for hygienic behavior, in honey bee colonies. We concluded that, while hygienic behavior was efficient against some brood diseases, it was difficult to draw any definitive conclusion on the efficiency of this behavior against V. destructor. Hygienic behavior likely contributes to Varroa-resistance, but the controversy is fueled by the use of inappropriate bioassays to quantify the hygienic removal of Varroa-infested brood. In our experiments, we showed that a commonly used bioassay, the freeze-killed brood removal bioassay, was unreliable to approximate the benefits arising from the hygienic removal of Varroa-infested brood. As an introduction to the second part of the thesis, we reviewed how human has contributed to reshape the diversity of honey bee populations worldwide, except in Africa. Human management was shown to increase the proportion of admixed populations, sometimes to the detriment of subspecies populations (such as in Belgium). Then, we presented a new approach to study the admixture of hybrid honey bee populations. It was based on a reduced representation of the genome (through genotyping-by-sequencing). In this approach, we enabled the use of pool-based sequencing data by simulating an individual genotype for each pool, sampled from a hybrid colony. Finally, some conclusions and discussion were brought on a few perspectives and research avenues about (1) the phenotyping of hygienic behavior towards Varroa-infested brood, and (2) the study of admixture in honey bee populations. [less ▲]

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See detailIntégration système et simulation
Hennaut, Samuel ULiege; Davin, Elisabeth ULiege; Baiwir, Romain ULiege et al

Scientific conference (2017, September 20)

Detailed reference viewed: 23 (3 ULiège)
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See detailÉmile de LAVELEYE (1822-1892) et le « bon » gouvernement
Grandjean, Geoffrey ULiege

Conference (2017, September 20)

Detailed reference viewed: 24 (3 ULiège)
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See detailBreed fast, die young - Demography of a Neotropical fossorial frog
Székely, Diana ULiege; Székely, Paul; Stănescu, Florina et al

Poster (2017, September 19)

Information regarding age- and size-related parameters is of paramount importance both to understanding the life-history of populations, and for designing effective conservation strategies; however, such ... [more ▼]

Information regarding age- and size-related parameters is of paramount importance both to understanding the life-history of populations, and for designing effective conservation strategies; however, such base-line data lacks for many species, especially for those inhabiting tropical habitats. Using skeletochronology, we provide the first detailed information regarding the demography of the Pacific horned frog, Ceratophrys stolzmanni, a vulnerable, fossorial amphibian, that lives in the Tumbesian dry-forests of Ecuador. The species shows an intense growth rate during the first activity season, both before and after metamorphosis. Sexual maturity is achieved by both sexes before the first year of life, after which growth rates abruptly decrease. Females are on average larger, but not older, than males, mean age being two years in both sexes. The rapid sexual maturation is associated with a short life-span, the observed maximum longevity being three years in males and four years in females. The short reproductive life-span, which offers few mating opportunities, might have important implications for the conservation of this species, that can be especially at risk in the case of prolonged droughts expected to affect its habitat. [less ▲]

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See detailStochastic multiscale modeling of MEMS stiction failure
Hoang Truong, Vinh ULiege

Doctoral thesis (2017)

In the context of microelectromechanical systems, due to their reduced size, the surface phenomena, e.g. adhesion contact, play an important role in the reliability of the devices. Indeed, the adhesive ... [more ▼]

In the context of microelectromechanical systems, due to their reduced size, the surface phenomena, e.g. adhesion contact, play an important role in the reliability of the devices. Indeed, the adhesive forces, e.g. capillary and van der Waal forces, can lead to the stiction failure for which the two contacting surfaces can accidentally be stuck together permanently. This is a common failure of MEMS. Because of the comparability between the roughness of the contacting surfaces and the ranges of adhesive stress, the interaction area can be much smaller than the apparent one. Since the contact zone is reduced and becomes comparable with the characteristic length scale of the surface roughness, the behaviors of micro structures subjected to adhesion suffer from a scatter, i.e. while some devices are unstuck, the others with an identical design are stuck. The objective of this work is to predict in a probabilistic way the adhesion behaviors of MEMS by accounting for the randomness of the contacting surfaces. The straightforward solution toward this end consists in constructing a numerical model, e.g. using finite element method, and in performing a Monte-Carlo simulation (MCS) directly on that model. Because the problem spans multiple scales, including the nanometers range of adhesive stress and the micrometers length scale of MEMS, that method demands a huge computational cost and becomes unpractical. In this work, a stochastic model-based multiscale method is developed to fulfill the predefined objective while remaining efficient in terms of computational cost. In this model, MCS is also per- formed, however, in a scale-by-scale way. With this method, the model is executed with acceptable computational cost. To verify the proposed model, a comparison in terms of the numerical predictions obtained from two approaches, direct MCS and stochastic model-based method, is performed. Furthermore, the model is applied to simulate the stiction tests reported in the literature, and also on the experimental surfaces fabri- cated by our partner at IMT-Bucharest lab 1 (without stiction test). By comparing the numerical predictions with the experimental results, the model is then validated. The model is used to broaden our knowledge in stiction phenomenon by considering the effects of the following aspects on the adhesion energies: the roughness of surfaces, the non-Gaussianity in the probability distribution of surface heights, and the humidity of the environment conditions. Furthermore, the comparison between different sources of uncertainty, e.g. due to the surfaces roughness and in the geometry dimensions of the devices, is performed. [less ▲]

Detailed reference viewed: 83 (27 ULiège)
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See detailThe Cassini-Huygens mission: tale of a 13-year journey in the Saturnian system
Palmaerts, Benjamin ULiege

Conference (2017, September 19)

On the 15th of September 2017, the Cassini spacecraft will plunge into the atmosphere of Saturn, making the end of the successful Cassini-Huygens mission. During this unprecedented mission, Cassini will ... [more ▼]

On the 15th of September 2017, the Cassini spacecraft will plunge into the atmosphere of Saturn, making the end of the successful Cassini-Huygens mission. During this unprecedented mission, Cassini will have spent 13 years around Saturn, achieving almost 300 orbits around the planet and continuously collecting observations of Saturn, its rings, moons and space environment. In this talk, after a short introduction about the genesis of the Cassini mission, I will give a review of all the important results of the mission. The dynamics of Saturn's atmosphere and magnetosphere will be discussed, as well as the discoveries about the evolution of the rings. An important part of the presentation will be also devoted to the moons Titan and Enceladus which both exhibit striking characteristics. [less ▲]

Detailed reference viewed: 21 (2 ULiège)
Peer Reviewed
See detailIdentification and quantitation of intact virus-like particles of human papillomavirus (HPV-VLP) using capillary electrophoresis
Bettonville, Virginie ULiege; Nicol, Jérôme; Furst, Tania et al

Conference (2017, September 19)

Detailed reference viewed: 39 (7 ULiège)
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See detailSimple LC Isocratic Methods Development, Validation, and Application in the Analysis of Poor Quality Antimalarial Medicines
Habyalimana, Védaste ULiege; Mbinze Kindenge, Jéremie; Yemoa Loconon, Achille et al

in American Journal of Analytical Chemistry (2017), 8

Liquid chromatographic methods in isocratic mode for the analysis of poor quality medicines are privileged due to their simplicity and facility in methods development. They are generally fast; do not need ... [more ▼]

Liquid chromatographic methods in isocratic mode for the analysis of poor quality medicines are privileged due to their simplicity and facility in methods development. They are generally fast; do not need to be re-equilibrated between sample injections; have larger flexibility with acceptable changes on different column dimensions; and are applicable to LC systems equipped with simple or high developed pumps. In this study, we focused on developing simple isocratic methods using classical mobile phase composed by methanol and ammonium formate buffer for the analysis of most common antimalarial medicines marketed in malaria endemic countries and susceptible of being counterfeit/falsified, substandard and degraded. The selected medicines were quinine and related cinchona alkaloids in tablets and injectable forms; artemether/ lumefantrine tablets; and artemisinin compounds (arteether, artemether, and artesunate) in injectable forms. The current methods were developed thanks to simple methodological approach consisting in sequential isocratic runs through adjustment or adaptation of existing methods to obtain optimal analytical conditions without complex design of experiments that might be long and costly. Then, the new methods presented shorter analysis time; allowed increase of sample analysis throughput; and obviously consumed little mobile phase solvents on classical analytical columns: 50 - 250 mm of length (L), 4.6 mm of internal diameter (I.D.), and 3.5 - 5.0 μm of particle size (dp). [less ▲]

Detailed reference viewed: 36 (1 ULiège)
See detailDecades of self-management: A story of distinctiveness and ideology
Soetens, Aurélie ULiege

Scientific conference (2017, September 19)

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See detaila journey through stable isotopes applications in trophic ecology
Lepoint, Gilles ULiege

Learning material (2017)

Detailed reference viewed: 9 (0 ULiège)
See detailRegards sur la crise politique francophone et perspectives pour les futures élections.
Verjans, Pierre ULiege

Conference given outside the academic context (2017)

La motion de méfiance constructive votée par le CDH à la Région wallonne aura des conséquences sur les prochaines élections s'ajoutant aux effets de la décrédibilisation du PS à la suite de la ... [more ▼]

La motion de méfiance constructive votée par le CDH à la Région wallonne aura des conséquences sur les prochaines élections s'ajoutant aux effets de la décrédibilisation du PS à la suite de la dénonciation des affaires Publifin et Samusocial. Peut-on anticiper ces effets? [less ▲]

Detailed reference viewed: 20 (0 ULiège)
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See detailIntroduction
Grodent, Denis ULiege

Learning material (2017)

Introduction

Detailed reference viewed: 63 (15 ULiège)
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See detailAtmospheric structure
Grodent, Denis ULiege

Learning material (2017)

Atmospheric structure

Detailed reference viewed: 45 (18 ULiège)
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Peer Reviewed
See detailDenitrification, anaerobic ammonium oxidation, and dissimilatory nitrate reduction to ammonium in an East African Great Lake (Lake Kivu)
Roland, Fleur ULiege; Darchambeau, François; Borges, Alberto ULiege et al

in Limnology and Oceanography (2017)

We investigated anaerobic nitrogen (N) cycling in the water column of Lake Kivu, a deep meromictic tropical lake in East Africa. Data were collected at one station in the Northern Basin and one in the ... [more ▼]

We investigated anaerobic nitrogen (N) cycling in the water column of Lake Kivu, a deep meromictic tropical lake in East Africa. Data were collected at one station in the Northern Basin and one in the Southern Basin, during two sampling campaigns (June 2011—dry season, and February 2012—rainy season). Short-term incubations of sulfide-free water with 15N-labeled substrates revealed high potential denitrification and dissimilatory nitrate reduction to ammonium (DNRA) rates (up to 350 and 36 nmol N produced L−1 h−1, respectively), while anaerobic ammonium oxidation (anammox) was lower (up to 3.3 nmol N produced L−1 h−1). However, anammox rates were 15 nmol N produced L−1 h−1 when 15 NH4+ was added at depths where NH4+ concentrations were very low (< 1 μmol L−1). With the addition of 5 μmol L−1 of 15 NO3− and 10 μmol L−1 of H2S, denitrification and anammox were stimulated in the Northern Basin, while the increase of DNRA rates was less notable. In the Southern Basin, the addition of H2S decreased denitrification rates, probably because of competition with DNRA, which increased, while no effect was observed on anammox. This study puts into evidence the co-occurrence of denitrification, anammox and DNRA, for the first time in a great tropical lake, and underlines the spatial heterogeneity of these processes. Contrary to numerous reports in literature, we show that anammox can significantly occur in presence of H2S, suggesting that the contribution of anammox in the N cycle may be underestimated. [less ▲]

Detailed reference viewed: 26 (4 ULiège)