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See detailAbelian bordered factors and periodicity
Charlier, Emilie ULg; Harju, Tero; Puzynina, Svetlana et al

in European Journal of Combinatorics (in press)

A finite word u is said to be bordered if u has a proper prefix which is also a suffix of u, and unbordered otherwise. Ehrenfeucht and Silberger proved that an infinite word is purely periodic if and only ... [more ▼]

A finite word u is said to be bordered if u has a proper prefix which is also a suffix of u, and unbordered otherwise. Ehrenfeucht and Silberger proved that an infinite word is purely periodic if and only if it contains only finitely many unbordered factors. We are interested in abelian and weak abelian analogues of this result; namely, we investigate the following question(s): Let w be an infinite word such that all sufficiently long factors are (weakly) abelian bordered; is w (weakly) abelian periodic? In the process we answer a question of Avgustinovich et al. concerning the abelian critical factorization theorem. [less ▲]

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See detailUPLC®-MS/MS, an analytical tool for the accurate and rapid quantification of phytoestrogen metabolites in milk
Daems, Frédéric ULg; Jasselette, Christophe; Romnee, Jean-Michel et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (in press)

The term ‘phytoestrogen’ is used to define a wide variety of nonsteroidal compounds that occur naturally in many plants. When they are absorbed by cows, these polyphenolic compounds undergo ... [more ▼]

The term ‘phytoestrogen’ is used to define a wide variety of nonsteroidal compounds that occur naturally in many plants. When they are absorbed by cows, these polyphenolic compounds undergo biotransformation by specific bacteria present in the gastrointestinal tract. The resulting metabolites are absorbed in the organism and some are excreted in milk. The impact of these compounds on human health divides opinion. Some scientists believe that they might have adverse health effects. Others believe the opposite, especially with regard to their microbial metabolites, such as equol. Whatever one's view on the subject, scientists need accurate, sensitive and rapid analytical methods in order to continue the research on clarifying the phytoestrogen issue. Cow's milk is an animal product that is common in the human diet, and it is therefore important to evaluate its content of phytoestrogen metabolites. In order to study the human intake of equol via commercial milk, an analytical method was developed and validated following EMA/CVMP/VICH/463202/2009 guidelines. Enzymatic hydrolysis was used to release the equol. It was then extracted using double liquid/liquid extraction and analyzed using UPLC®-MS/MS, with an analysis runtime of only 5 min. This analytical method produced a linear calibration curve with a high correlation coefficient (R2≥0.996) between 5 and 1,000 ng mL−1. Good intra- and inter-day precision (RSDs≤5.3% and ≤5.2%, respectively) and accuracy (bias≤8.6%) were achieved. The recovery rate differed slightly among the different types of milk, ranging between 60.6±1.09% and 82.3±5.21%. Good method repeatability was observed (RSDs<15%). There was neither a matrix effect nor a carry-over effect, and the sample extracts were stable during storage for at least 7 days at −21°C and 5°C. In order to apply the proposed method and obtain an initial estimate of equol concentration in cow’s milk in Belgium, 44 samples of various brands found in several supermarkets and 5 raw milk samples from Walloon farms were analyzed. Equol was found in all the samples analyzed, with a concentration ranging from 10 to 50 ng mL−1 for conventional milk and from 70 to 130 ng mL−1 for organic milk. These results were compared with other European studies and the same trend was observed. The results obtained show the specificity, sensitivity and precision of this method for analyzing oestrogenic metabolite-equol in cow’s milk. This study should be extended to include a greater number of samples and be implemented over a longer period to see if there is a correlation between livestock practice and/or sample origins with the equol content in milk. The addition of other phytoestrogen compounds with this method, using UPLC®-MS/MS technology, could also lead to more reliable monitoring of these compounds in dairy production. [less ▲]

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See detailQue peut la rhétorique pour les études francophones ?, ou comment étudier les enjeux de catégorisation et d’institutionnalisation
Provenzano, François ULg

in Anders Baggesgaard, Mads; Verstraete-Hansen, Lisbeth (Eds.) Le monde en français – les littératures francophones dans un espace mondialisé (in press)

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See detailProjections photographiques et cinéma des premiers temps : La houillère de Gustave Marissiaux et les origines du cinéma minier
Mélon, Marc-Emmanuel ULg

in Intermédialités : Histoire et Théorie des Arts, des Lettres et des Techniques = Intermediality: History and Theory of the Arts, Literature and Technologies (in press)

Les spectacles de projection conçus par Gustave Marissiaux entre 1903 et 1926, en particulier le vaste documentaire intitulé "La houillère" (1905) est ici inscrit dans une histoire sociale des images ... [more ▼]

Les spectacles de projection conçus par Gustave Marissiaux entre 1903 et 1926, en particulier le vaste documentaire intitulé "La houillère" (1905) est ici inscrit dans une histoire sociale des images projetées et mis en rapport avec le cinéma minier des premiers temps [less ▲]

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See detailSomatotrope GHRH/GH/IGF-1 axis at the crossroad between immunosenescence and elder frailty
Bodart, Gwennaëlle ULg; Goffinet, Lindsay; Morrhaye, Gabriel et al

in Annals of the New York Academy of Sciences (in press)

Immunosenescence as complex modifications of immunity with age could be related to the so-called frailty syndrome of elderly leading to an inadequate response to minimal aggression. Functional decline ... [more ▼]

Immunosenescence as complex modifications of immunity with age could be related to the so-called frailty syndrome of elderly leading to an inadequate response to minimal aggression. Functional decline, the loss of ability to perform activities of daily living, is related to the decrease in physiological reserves and frailty and is a frequent outcome of hospitalization in older patients. Links between immunosenescence and frailty were explored and 20 immunological parameters were affected in seniors with functional decline. IGF-1, thymopoeisis and telomere length were part of these markers. A strong relationship between insulin-like growth factor-1 (IGF-1) and thymic ouput was evidenced. IGF-1, mediator of GH, was subsequently shown to induce IL-7 secretion in cultured primary human thymic epithelial cells (TECs). We are also exploring the ‘stress hypothesis’ according which an acute stress is the discriminator revealing a frailty susceptility. GH can counteract the deleterious immunosuppressive effect of stress-induced steroids. Under non-stressing conditions, the immunosenescent system preserves physiological responses, while in stressing conditions, the combination of immunosenescence and a defect in somatotrope axis might lead to functional decline. [less ▲]

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See detailD’un décor à l’autre, d’un commanditaire à l’autre. À la recherche du commanditaire des peintures murales de Bois
Marchandisse, Alain ULg; Masson, Christophe ULg

in Peintures murales du XVe siècle dans la Principauté de Liège. Regards croisés sur la chapelle castrale de Ponthoz et l’église de Bois (in press)

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See detailD’un décor à l’autre, d’un commanditaire à l’autre. Wautier de Corswarem, un commanditaire très discret…
Marchandisse, Alain ULg; Masson, Christophe ULg

in Peintures murales du XVe siècle dans la Principauté de Liège. Regards croisés sur la chapelle castrale de Ponthoz et l’église de Bois (in press)

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See detailEffect of wheel traffic on the physical properties of a Luvisol
Destain, Marie-France ULg; Roisin, Christian; Dalcq, Anne-Catherine ULg et al

in Geoderma (in press)

The effects of machine traffic were assessed on a Luvisol in a temperate climate area in Belgium. Soil samples were taken from topsoil (0.07-0.25 m) and subsoil (0.35-0.50 m), on plots under long-term ... [more ▼]

The effects of machine traffic were assessed on a Luvisol in a temperate climate area in Belgium. Soil samples were taken from topsoil (0.07-0.25 m) and subsoil (0.35-0.50 m), on plots under long-term reduced tillage (RT) and conventional tillage (CT). Cone index (CI), bulk density (BD) and precompression stress (Pc) were chosen as indicators of mechanical strength. Mercury intrusion porosimetry was used to characterize the soil microporosity structure. It was presented in two forms: (i) cumulative pore volume vs. equivalent pore radius r, from which four classes of porosity were defined: r < 0.2 μm, 0.2 ≤ r < 9 µm, 9 ≤ r < 73 µm and r ≥ 73 μm; (ii) pore-size distribution (PSDs). In the reference situation where there had been no recent passage of machines, the voids with 0.2 ≤ r < 9 µm were the most important class in RT topsoil. The voids with r ≥ 73 µm represented the main porosity class in the topsoil of CT. In the subsoil, for both tillage systems, the porosity was almost equally distributed between voids with 0.2 ≤ r < 9 µm and voids with r greater than 9 µm. Machine traffic was carried out when the soil water content was close to the optimum Proctor. Although unfavourable, these wet conditions often occur during the beet harvesting period in Belgium. The highest modifications in soil structure (increase in BD and Pc, reduction of macroporosity r ≥ 73 μm) were observed in the topsoil of CT. More limited modifications were noticed in the soil structure of RT topsoil and subsoil layers but these latter are problematic in that the soil would no longer be loosened by subsequent tillage. These modifications could lead to soil consolidation as a result of wheel traffic year after year. [less ▲]

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See detailRisk assessment of soil compaction in the Walloon region in Belgium
D'Or, Dimitri; Destain, Marie-France ULg

in Mathematical Geosciences (in press)

It is well known that soil compaction affects root growth and disrupts the activity of soil microfauna and microorganisms, resulting in yield loss. With the more intensive use of heavy machines in ... [more ▼]

It is well known that soil compaction affects root growth and disrupts the activity of soil microfauna and microorganisms, resulting in yield loss. With the more intensive use of heavy machines in agriculture and forestry, the risk of soil compaction is increasing. In this study, precompression stress (Pc) was chosen as an indicator of the susceptibility of soils to compaction and was calculated using pedotransfer functions (PTFs). PTFs involve eight variables related to the hydraulic and mechanical behaviour of soils: organic matter content; bulk density; air capacity; available water capacity; non-plant available water capacity; saturated hydraulic conductivity; cohesion; and angle of internal friction. Combining these PTFs with geostatistics and Monte Carlo simulations, Pc maps were produced at the regional scale for Wallonia in Belgium, accompanied by uncertainty quantification maps. These maps were then used to produce compaction risk maps based on common scenarios. The results showed that the modal Pc map was coherent with the spatial distribution of the main variables, namely soil texture and organic matter content. The risk maps enabled areas with a compaction risk in both agricultural and forestry contexts to be identified. These maps could be useful in drawing up soil protection measures and policies. [less ▲]

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See detailStroboscopic phenomena in superconductors with dynamic pinning landscape
Jelic, Zeljko ULg; Milosevic, Milorad; Van de Vondel, Joris et al

in Scientific Reports (in press)

Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain ... [more ▼]

Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain without dissipation. In case of spatially periodic pinning, a clear enhancement of the superconducting critical current arises when commensurability between the vortex configurations and the pinning landscape occurs. With recent achievements in (ultrafast) optics and nanoengineered plasmonics it has become possible to exploit the interaction of light with superconductivity, and create not only spatially periodic imprints on the superconducting condensate, but also temporally periodic ones. Here we show that in the latter case, temporal matching phenomena develop, caused by stroboscopic commensurability between the characteristic frequency of the vortex motion under applied current and the frequency of the dynamic pinning. The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics. All features are tunable by the frequency of the dynamic pinning landscape. These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities. [less ▲]

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See detailLe touriste à la ferme : de la thématisation au simulacre ?
Dubois, Charline ULg; Schmitz, Serge ULg

in Sarrasin, B.; Decroly, Jean-Michel (Eds.) Rendez-vous Champlain sur le Tourisme - L'expérience touristique (in press)

Although farm tourism is an appealing idea combining agriculture and tourism, the chance to succeed in both activities is low. The Farm tourism experiments are supplied, imagined and experimented in ... [more ▼]

Although farm tourism is an appealing idea combining agriculture and tourism, the chance to succeed in both activities is low. The Farm tourism experiments are supplied, imagined and experimented in different ways. Consequently definitions, practices and perceptions of agritourism or farm tourism differ as well. Using Gunn’s image typology the paper analyses induced, organic and modified by experience images of argitourism. The study combines data issued from a survey amongst tourists (n = 230), 26 tourism farm holders’ life stories and 31 interviews with experts conducted both in Wallonia and Grand Duchy of Luxembourg. It scrutinizes the promotional discourses, the life experience and the strategy of farm tourism holders, the expectations of tourists who have experimented farm tourism or not, who claim living in the countryside or not. The level of expectations regarding reception, authenticity, convenience, and active participation in farm works differ noticeably and are now and then inconsistent with the supply and the farm activity. [less ▲]

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See detailDouble hydrophilic polyphosphoester containing copolymers as efficient templating agents for calcium carbonate microparticles
Ergül, Zeynep ULg; Debuigne, Antoine ULg; Calvignac, Brice et al

in Journal of Materials Chemistry B (in press)

The use of calcium carbonate (CaCO3) microparticles is becoming more and more attractive in many fields especially in biomedical applications in which the fine tuning of the size, morphology and ... [more ▼]

The use of calcium carbonate (CaCO3) microparticles is becoming more and more attractive in many fields especially in biomedical applications in which the fine tuning of the size, morphology and crystalline form of the CaCO3 particles is crucial. Although some structuring compounds, like hyaluronic acid, give satisfying results, the control of the particle structure still has to be improved. To this end, we evaluated the CaCO3 structuring capacity of novel well-defined double hydrophilic block copolymers composed of poly(ethylene oxide) and a polyphosphoester segment with an affinity for calcium like poly(phosphotriester)s bearing pendent carboxylic acids or poly(phosphodiester)s with a negatively charged oxygen atom on each repeating monomer unit. These copolymers were synthesized by a combination of organocatalyzed ring opening polymerization, thiol–yne click chemistry and protection/deprotection methods. The formulation of CaCO3 particles was then performed in the presence of these block copolymers (i) by the classical chemical pathway involving CaCl2 and Na2CO3 and (ii) by a process based on supercritical carbon dioxide (scCO2) technology in which CO32− ions are generated in aqueous media and react with Ca2+ ions. Porous CaCO3 microspheres composed of vaterite nanocrystals were obtained. Moreover, a clear dependence of the particle size on the structure of the templating agent was emphasized. In this work, we show that the use of the supercritical process and the substitution of hyaluronic acid for a carboxylic acid containing copolymer decreases the size of the CaCO3 particles by a factor of 6 (∼1.5 μm) while preventing their aggregation. [less ▲]

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See detailMyoferlin plays a key role in VEGFA secretion and impacts tumor-associated angiogenesis in human pancreas cancer
Fahmy, Karim ULg; Gonzalez, Arnaud; Arafa, Mohammad et al

in International Journal of Cancer = Journal International du Cancer (in press)

Pancreatic ductal adenocarcinoma is one of the most deadly forms of cancers with no satisfactory treatment to date. Recent studies have identified myoferlin, a ferlin family member, in human pancreas ... [more ▼]

Pancreatic ductal adenocarcinoma is one of the most deadly forms of cancers with no satisfactory treatment to date. Recent studies have identified myoferlin, a ferlin family member, in human pancreas adenocarcinoma where its expression was associated to a bad prognosis. However, the function of myoferlin in pancreas adenocarcinoma has not been reported. In other cell types, myoferlin is involved in several key plasma membrane processes such as fusion, repair, endocytosis and tyrosine kinase receptor activity. In this study, we showed that myoferlin silencing in BxPC-3 human pancreatic cancer cells resulted in the inhibition of cell proliferation in vitro and in a significant reduction of the tumor volume in chick chorioallantoic membrane assay. In addition to be smaller, the tumors formed by the myoferlin-silenced cells showed a marked absence of functional blood vessels. We further demonstrated that this effect was due, at least in part, to an inhibition of VEGFA secretion by BxPC-3 myoferlin-silenced cells. Using immunofluorescence and electron microscopy, we linked the decreased VEGFA secretion to an impairment of VEGFA exocytosis. The clinical relevance of our results was further strengthened by a significant correlation between myoferlin expression in a series of human pancreatic malignant lesions and their angiogenic status evaluated by the determination of the blood vessel density. [less ▲]

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See detailLes croyances délétères des patients lombalgiques : revue narrative de la littérature
Demoulin, Christophe ULg; Roussel, Nathalie; Marty, Marc et al

in Revue Médicale de Liège (in press)

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See detailXenobiotic and Immune-Relevant Molecular Biomarkers in Harbor Seals as Proxies for Pollutant Burden and Effects?
Lehnert, Kristina; Ronnenberg, Katrin; Weijs, Liesbeth et al

in Archives of Environmental Contamination & Toxicology (in press)

Harbor seals are exposed to increasing pressure caused by anthropogenic activities in their marine environment. Persistent organic pollutants (POPs) and trace elements are hazardous contaminants which ... [more ▼]

Harbor seals are exposed to increasing pressure caused by anthropogenic activities in their marine environment. Persistent organic pollutants (POPs) and trace elements are hazardous contaminants which accumulate in tissues of harbor seals. POPs and trace elements can negatively affect the immune-system and have been reported e.g. to increase susceptibility to viral infections in seals. Biomarkers of the xenobiotic metabolism, cytokines and heat-shock-protein as cell mediators of the immune-system were established to evaluate the impact of environmental stressors on harbor seals. Harbor seals (n=54) were captured on sandbanks in the North Sea during 2009 to 2012. Medicals including hematology were performed, RNAlater blood samples were taken and analyzed using quantitative Polymerase Chain Reaction. Normalized transcript copy numbers were correlated to hematology and POP concentration in blood, and trace metals in blood and fur. [less ▲]

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See detailAn incremental-secant mean-field homogenisation method with second statistical moments for elasto-plastic composite materials
Wu, Ling ULg; Doghri, Issam; Noels, Ludovic ULg

in Philosophical Magazine (in press)

In this paper, the incremental-secant mean-field homogenisation (MFH) scheme recently developed by the authors is extended to account for second statistical moments. The incremental-secant MFH method ... [more ▼]

In this paper, the incremental-secant mean-field homogenisation (MFH) scheme recently developed by the authors is extended to account for second statistical moments. The incremental-secant MFH method possesses several advantages compared to other MFH methods. Indeed the method can handle non-proportional and non-monotonic loadings, while the instantaneous stiffness operators used in the Eshelby tensor are naturally isotropic, avoiding the isotropisation approximation required by the affne and incremental-tangent methods. Moreover, the incremental-secant MFH formalism was shown to be able to account for material softening when extended to include a non-local damage model in the matrix phase, thus enabling an accurate simulation of the onset and evolution of damage across the scales. In this work, by accounting for a second statistical moment estimation of the current yield stress in the composite phases, the plastic flow computation allows capturing with a better accuracy the plastic yield in the composite material phases, which in turn improves the accuracy of the predictions, mainly in the case of short fibre composite materials. The incremental-secant mean-field-homogenisation (MFH) can thus be used to model a wide variety of composite material systems with a good accuracy. [less ▲]

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See detailContribution of distribution network control to voltage stability: A case study
Aristidou, Petros ULg; Valverde, Gustavo; Van Cutsem, Thierry ULg

in IEEE Transactions on Smart Grid (in press)

A case study dealing with long-term voltage instability in systems hosting active distribution networks is reported in this paper. It anticipates future situations with high penetration of dispersed ... [more ▼]

A case study dealing with long-term voltage instability in systems hosting active distribution networks is reported in this paper. It anticipates future situations with high penetration of dispersed generation, where the latter are used to keep distribution voltages within desired limits, in complement to load tap changers. The interactions between transmission and active distribution networks are investigated on a 3108-bus test system. It involves transmission grid, large generators, and forty distribution networks, each with dispersed generation steered by a controller inspired of model predictive control. The reported simulations show the impact of distribution network voltage restoration as well as the benefit of load voltage reduction actuated by the dispersed generators. [less ▲]

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See detailDetection of anthropogenic particles in fish stomachs: an isolation method adapted to identification by Raman spectroscopy
Collard, France ULg; Gilbert, Bernard ULg; Eppe, Gauthier ULg et al

in Archives of Environmental Contamination & Toxicology (in press)

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See detailUsing seismic inversions to obtain an indicator of internal mixing processes in main-sequence solar-like stars
Buldgen, Gaël ULg; Dupret, Marc-Antoine ULg; Reese, Daniel Roy

in Astronomy and Astrophysics (in press)

Context. Currently, seismic modelling is one of the best ways of building accurate stellar models, thereby providing accurate ages. However, current methods are affected by simplifying assumptions ... [more ▼]

Context. Currently, seismic modelling is one of the best ways of building accurate stellar models, thereby providing accurate ages. However, current methods are affected by simplifying assumptions concerning stellar mixing processes. In this context, providing new structural indicators that are less model-dependent and more sensitive to mixing processes is crucial. Aims. We wish to build a new indicator for core conditions (i.e. mixing processes and evolutionary stage) on the main sequence. This indicator tu should be more sensitive to structural differences and applicable to older stars than the indicator t presented in a previous paper. We also wish to analyse the importance of the number and type of modes for the inversion, as well as the impact of various constraints and levels of accuracy in the forward modelling process that is used to obtain reference models for the inversion. Methods. First, we present a method of obtaining new structural kernels in the context of asteroseismology. We then use these new kernels to build a new indicator of central conditions in stars, denoted tu, and test it for various effects including atomic diffusion, various initial helium abundances, and various metallicities, following the seismic inversion method presented in our previous paper. We then study the indicator’s accuracy for seven different pulsation spectra including those of 16CygA and 16CygB and analyse how it depends on the reference model by using different constraints and levels of accuracy for its selection Results. We observe that the inversion of the new indicator tu using the SOLA method provides a good diagnostic for additional mixing processes in central regions of stars. Its sensitivity allows us to test for diffusive processes and chemical composition mismatch. We also observe that using modes of degree 3 can improve the accuracy of the results, as well as using modes of low radial [less ▲]

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