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Liege, Belgium

The University of Liège , in Liège, Wallonia, Belgium, is a major public university in the French Community of Belgium. Its official language is French. Wikipedia.

Scheen A.J.,University of Liege
Expert Opinion on Pharmacotherapy | Year: 2012

Introduction: Dipeptidylpeptidase-4 (DPP-4) inhibitors offer new options for the management of type 2 diabetes (T2DM). Areas covered: This paper is an updated review, providing an analysis of both the similarities and the differences between the various compounds known as gliptins, currently used in the clinic (sitagliptin, vildagliptin, saxagliptin, alogliptin and linagliptin). This paper discusses the pharmacokinetic and pharmacodynamic characteristics of gliptins; both the efficacy and safety profiles of gliptins in clinical trials (compared with classical glucose-lowering agents), given as monotherapy or in combination, including in special populations; the positioning of DPP-4 inhibitors in the management of T2DM in recent guidelines; and various unanswered questions and perspectives. Expert opinion: The role of DPP-4 inhibitors in the therapeutic armamentarium of T2DM is evolving, as their potential strengths and weaknesses become better defined. Future critical issues may include the durability of glucose control, resulting from better β-cell protection, positive effects on cardiovascular outcomes and long-term safety issues. Source

Scheen A.J.,University of Liege | Scheen A.J.,The Interdisciplinary Center
Expert Opinion on Drug Safety | Year: 2015

Introduction: Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) occupy a growing place in the armamentarium of drugs used for the management of hyperglycemia in type 2 diabetes, although some safety concerns have been raised in recent years.Areas covered: An updated review providing an analysis of available safety data (meta-analyses, randomized controlled trials, observational cohort and case-control studies and pharmacovigilance reports) with five commercialized DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin, alogliptin, linagliptin). A special focus is given to overall safety profile; pancreatic adverse events (AEs) (acute pancreatitis, pancreatic cancer); overall cardiovascular safety (myocardial infarction and stroke); congestive heart failure concern and finally, safety in special populations (elderly, renal impairment).Expert opinion: The good tolerance/safety profile of DPP-4 inhibitors has been largely confirmed, including in more fragile populations (elderly, renal impairment) with almost no increased risk of infection or gastrointestinal AEs, no weight gain and a minimal risk of hypoglycemia. Although an increased risk of acute pancreatitis and pancreatic cancer was suspected, the complete set of available data appears reassuring so far. Cardiovascular safety of DPP-4 inhibitors has been proven but an unexpected increased risk of heart failure has been reported which should be confirmed in ongoing trials and better understood. Further postmarketing surveillance is recommended. © 2015 Informa UK, Ltd. Source

Frederich B.,University of Liege | Sheets H.D.,Canisius College
Biological Journal of the Linnean Society | Year: 2010

The evolution of body size, the paired phenomena of giantism and dwarfism, has long been studied by biologists and paleontologists. However, detailed investigations devoted to the study of the evolution of ontogenetic patterns shaping giant species are scarce. The damselfishes of the genus Dascyllus appear as an excellent model for such a study. Their well understood phylogeny reveals that large-bodied species have evolved in two different clades. Geometric morphometric methods were used to compare the ontogenetic trajectories of the neurocranium and the mandible in both small-bodied (Dascyllus aruanus and Dascyllus carneus; maximum size: 50-65 mm standard length) and giant (Dascyllus trimaculatus and Dascyllus flavicaudus; maximum size: 90-110 mm standard length) Dascyllus species. At their respective maximum body size, the neurocranium of the giant species is significantly shorter and have a higher supraoccipital crest relative to the small-bodied species, whereas mandible shape variation is more limited and is not related to the 'giant' trait. The hypothesis of ontogenetic scaling whereby the giant species evolved by extending the allometric trajectory of the small-bodied ones (i.e. hypermorphosis) is rejected. Instead, the allometric trajectories vary among species by lateral transpositions. The rate of shape changes and the type of lateral transposition also differ according to the skeletal unit among Dascyllus species. Differences seen between the two giant species in the present study demonstrate that giant species may appear by varied alterations of the ancestor allometric pattern. © 2009 The Linnean Society of London. Source

Gassner M.,Ecole Polytechnique Federale de Lausanne | Vogel F.,Paul Scherrer Institute | Heyen G.,University of Liege | Marechal F.,Ecole Polytechnique Federale de Lausanne
Energy and Environmental Science | Year: 2011

Based on a previously developed thermo-economic process model, this paper presents a detailed design study for the polygeneration of Synthetic Natural Gas (SNG), power and heat by catalytic hydrothermal gasification of biomass and biomass wastes in supercritical water. Using multi-objective optimisation techniques, the thermodynamic and thermo-economic performances of all candidate configurations from a general process superstructure are optimised with respect to SNG and electricity cogeneration and its associated investment cost, production cost and plant profitability. The paper demonstrates how both the optimal system configuration, its operating conditions and performances depend on the available technology, catalyst lifetime, process scale and the characteristics of the processed substrate. © The Royal Society of Chemistry 2011. Source

Meyer T.,Max Planck Institute for Chemistry | Gabelica V.,University of Liege | Grubmuller H.,Max Planck Institute for Chemistry | Orozco M.,Institute for Research in Biomedicine
Wiley Interdisciplinary Reviews: Computational Molecular Science | Year: 2013

Proteins are complex macromolecules that evolved over billions of years to be active in aqueous solution. Water is a key element that stabilizes their structure, and most structural studies on proteins have thus been carried out in aqueous environment. However, recent experimental approaches have opened the possibility to gain structural information on proteins from gas-phase measurements. The obtained results revealed significant structural memory in proteins when transferred from water to the gas phase. However, after several years of experimental and theoretical research, the nature of the structural changes induced by vaporization, the exact characteristics of proteins in the gas phase, and the physicochemical forces stabilizing dehydrated proteins are still unclear. We will review here these issues using both experimental and theoretical sources of information. © 2012 John Wiley & Sons, Ltd. Source

Therapeutic inertia is one of the components of clinical inertia. It mainly concerns the management of chronic diseases. It may be defined as the attitude of health care providers who do not initiate or intensify therapy appropriately despite recognition of the problem. Multiple causes may be identified, related to the physician but also to the patient and to the health care system. The consequences may be dramatic, both for the patient, in terms of quality of life and/or life expectancy, and for the society, because of the huge cost resulting from complications due to therapeutic inertia. Thus, various solutions should be proposed to help solving this important public health problem, focusing the actions on the physician, the patient and/or the health care system. Source

De Becker M.,University of Liege
Astrophysics and Space Science | Year: 2014

Astrochemistry is the discipline that studies physico-chemical processes in astrophysical environments. Such environments are characterized by conditions that are substantially different from those existing in usual chemical laboratories. Models which aim to explain the formation of molecular species in interstellar environments must take into account various factors, including many that are directly, or indirectly related to the populations of massive stars in galaxies. The aim of this paper is to review the influence of massive stars, whatever their evolution stage, on the physico-chemical processes at work in interstellar environments. These influences include the ultraviolet radiation field, the production of high energy particles, the synthesis of radionuclides and the formation of shocks that permeate the interstellar medium. © 2013 Springer Science+Business Media Dordrecht. Source

Brock O.,Netherlands Institute for Neuroscience | Brock O.,Group 47 | Bakker J.,Netherlands Institute for Neuroscience | Bakker J.,VU University Amsterdam | Bakker J.,University of Liege
Endocrinology | Year: 2013

In rodents, kisspeptin-expressing neurons are localized in 2 hypothalamic brain nuclei (anteroventral periventricular nucleus/periventricular nucleus continuum [AVPv/PeN] and arcuate nucleus [ARC]) and modulated by sex steroids. By using wild-type (WT) and aromatase knockout (ArKO) mice (which cannot convert testosterone into estradiol) and immunohistochemistry, we observed that WT females showed a continuous increase in kisspeptin peptide expression in the ARC across postnatal ages (postnatal day 5 [P5] to P25), whereasWTmales did not show any expression before P25. Kisspeptin peptide expression was also present in ArKO females but did not increase over this early postnatal period, suggesting that kisspeptin peptide expression in the ARC is organized by estradiol-dependent and -independent mechanisms. We also compared kisspeptin peptide expression between groups of adult male and female mice that were left gonadally intact or gonadectomized and treated or not with estradiol (E2) or DHT. In the ARC, kisspeptin peptide expression decreased after gonadectomy but was completely rescued by either E2 or DHT treatment in each sex/genotype. However, kisspeptin peptide expression was lower in ArKO compared withWT subjects. In the AVPv/PeN, ArKO females showed a male-typical kisspeptin peptide expression, and adult E2 treatment partially restored kisspeptin peptide expression. Finally, we showed that, after E2 treatment ofWTand ArKO mice between either P5 and P15 or P15 and P25, AVPv/PeN kisspeptin peptide expression could be still masculinized at P5, but was feminized from P15 onward. In conclusion, the 2 kisspeptin neuronal populations (AVPv/PeN vs ARC) seem to be differentially organized and activated by E2. © 2013 by The Endocrine Society. Source

Garcia Muro V.J.,CONICET | Rubinstein C.V.,CONICET | Steemans P.,University of Liege
Geological Magazine | Year: 2014

This study is concentrated on Ludlow (to Pridoli?) miospores from the Los Espejos Formation at the Quebrada Ancha locality, Central Precordillera, San Juan Province, Argentina. The Ludlow age is in agreement with the age based on acritarchs. The assemblage of continental palynomorphs is composed of 43 miospore species (29 trilete spores and 14 cryptospores). A new synonymy is proposed: Chelinospora poecilomorpha is here considered a junior synonym of Clivosispora verrucata. In addition, specimens belonging to C. verrucata var. verrucata and C. verrucata var. convoluta are included in a new morphon. This study represents the second Late Silurian miospore assemblage described from South America; the first was from the Urubu River, Amazon Basin, northern Brazil. The Quebrada Ancha assemblages allow a reasonably good correlation with biozones established for the Upper Silurian from the Cantabrian Mountains, northern Spain. The dendrogram analysis between coeval miospore assemblages from different localities shows a strong palaeogeographic affinity with the miospores recovered from northern Brazil and North Africa. Miospore assemblages from Spain show influences from Baltica and North Africa, demonstrating their intermediate position between these two continental plates. Conversely, dissimilarities recognized between Libya and Tunisia are most probably owing to local ecology and/or environmental conditions. © Cambridge University Press 2013. Source

Rossi B.,University of Liege | Rasmussen K.J.R.,University of Sydney
Journal of Structural Engineering (United States) | Year: 2013

The strength of thin-walled stainless steel columns has been investigated extensively over the last few years. In European standards, the concept of section classification for determining the cross section capacity is used. In this system, for Class 4 cross sections, the effective width method (EWM) must be used to account for the effect of local buckling. Because of the complexity and limitations of this method, other methods have been developed, such as the direct strength method (DSM) for cold-formed thin-walled profiles and the continuous strength method (CSM), initially established for members made of nonlinear metallic materials. In the CSM, to take advantage of strain hardening, a deformation-based design approach using a continuous relationship between the cross-sectional slenderness and the cross-sectional deformation capacity is used. To a large extent, the CSM yields accurate predictions, especially in the low slenderness range where the current DSM design procedures for members submitted to pure compression tend to produce conservative predictions for materials with pronounced strain hardening such as stainless steel alloys. The present paper presents an extension of the traditional DSM, which provides accurate design strength predictions in the low slenderness range for stainless steel thin-walled section columns failing by distortional, local, and overall buckling. It contains practical information concerning the reference experimental data and draws conclusions about the justification of the proposed analytical formula. The paper is divided into three main parts: the description of the database, the establishment of the design model, and a reliability analysis of the method. © 2013 American Society of Civil Engineers. Source

Demoulin A.,Fund for Scientific Research FSR FNRS | Demoulin A.,University of Liege
Geomorphology | Year: 2011

Geomorphometry may be a powerful tool to describe the characteristics of the landscape's response to tectonic signals, but the meaning of morphometric indices is often obscured by the interplay between the many variables controlling the geomorphological evolution. Moreover, although the so-called hypsometric integral refers to the basin scale, most indices are generally derived from the river long profiles and thus focus mainly on the short-term response of a drainage network to base level change, providing limited information in regions of older and/or moderate uplift. Here, using the Rhenish shield (western Europe), an area of moderate Quaternary uplift, as a test case, I attempt to build an index yielding a comprehensive view of the stage attained by the landscape's response and, indirectly, an evaluation of the timing of the triggering base level change. This index, called R1, is a ratio of differences between the three integrals linked respectively to the classical basin's hypsometric curve, to the main river's long profile, and at the intermediate level, to a 'drainage network's hypsometric curve'. While its ratio form minimizes the lithological effect on R1, this index is strongly correlated with basin size (regional correlation coefficients are in the range 0.88-0.93), reflecting the way an erosion wave propagates from the outlet of a basin toward its headwaters. Therefore, it is not directly usable as a proxy for relative uplift age. However, one can show that the relation between R1 and basin size is theoretically expected to change with time. Following uplift, the slope Sr of the linear relation R1=f(lnA) first increases rapidly but briefly, then it gradually diminishes over several million years. This is fully confirmed by the analysis of R1 and Sr in the study area. Once its initial increase is completed (assumedly in a few ten thousand years), Sr appears to be a reliable indicator of relative uplift (or any other cause of base level lowering) age. © 2010 Elsevier B.V. Source

Hugnot J.P.,French Institute of Health and Medical Research | Hugnot J.P.,Montpellier University | Franzen R.,University of Liege
Frontiers in Bioscience | Year: 2011

In the brain, specific signalling pathways localized in highly organized regions called niches, allow the persistence of a pool of stem and progenitor cells that generate new neurons and glial cells in adulthood. Much less is known on the spinal cord central canal niche where a sustained adult neurogenesis is not observed. Here we review our current knowledge of this caudal niche in normal and pathological situations. Far from being a simple layer of homogenous cells, this region is composed of several cell types localized at specific locations, expressing characteristic markers and with different morphologies and functions. We further report on a screen of online geneexpression databases to better define this spinal cord niche. Several genes were found to be preferentially expressed within or around the central canal region (Bmp6, CXCR4, Gdf10, Fzd3, Mdk, Nrtn, Rbp1, Shh, Sox4, Wnt7a) some of which by specific cellular subtypes. In depth characterization of the spinal cord niche constitutes a framework to make the most out of this endogenous cell pool in spinal cord disorders. Source

Canagliflozin is an inhibitor of sodium-glucose cotransporters type 2 (SGLT2) that are present in renal tubules. This specific insulin-independent mechanism promotes glucosuria, which results in a reduction in fasting and postprandial glycaemia and a decrease of glycated haemoglobin (HbA1c). Furthermore, canagliflozin promotes weight loss and lowers arterial (mainly systolic) blood pressure. Its efficacy is decreased in patients with renal insufficiency and the treatment should be stopped if estimated glomerular filtration rate is below 45 ml/min/1.73 m2. Both the efficacy and safety of canagliflozin have been investigated in 24 to 104-week controlled trials versus placebo or versus an active comparator (glimepiride or sitagliptin). The mean reduction in HbA1c averages 0.75% when added to other treatments, as compared to placebo. The 100 mg dose is as active as sitagliptin 100 mg while the 300 mg canagliflozin dose is even more efficacious. Adverse events are mostly mycotic genital infections and more rarely mild urinary tract infections. Caution is required in elderly patients and the risk of volume depletion should be checked (hypotension). Hypoglycaemia may occur only in patients already treated with an insulin-secreting agent or insulin. Canagliflozin is commercialized under the trade name Invokana® , at the doses of 100 mg and 300 mg once daily, for the treatment of type 2 diabetes. Source

Mancusi D.,University of Liege | Charity R.J.,Washington University in St. Louis | Cugnon J.,Washington University in St. Louis
Physical Review C - Nuclear Physics | Year: 2010

We present a statistical-model description of fission, in the framework of compound-nucleus decay, which is found to simultaneously reproduce data from both heavy-ion-induced fusion reactions and proton-induced spallation reactions at around 1 GeV. For the spallation reactions, the initial compound-nucleus population is predicted by the Liège intranuclear cascade model. We are able to reproduce experimental fission probabilities and fission-fragment mass distributions in both reactions types with the same parameter sets. However, no unique parameter set was obtained for the fission probability. The introduction of fission transients can be offset by an increase of the ratio of level-density parameters for the saddle-point and ground-state configurations. Changes to the finite-range fission barriers could be offset by a scaling of the Bohr-Wheeler decay width as predicted by Kramers. The parameter sets presented allow accurate prediction of fission probabilities for excitation energies up to 300 MeV and spins up to 60 h{stroke}. © 2010 The American Physical Society. Source

Gassner M.,Ecole Polytechnique Federale de Lausanne | Vogel F.,Paul Scherrer Institute | Heyen G.,University of Liege | Marechal F.,Ecole Polytechnique Federale de Lausanne
Energy and Environmental Science | Year: 2011

This paper presents a process model for the polygeneration of Synthetic Natural Gas (SNG), power and heat by catalytic hydrothermal gasification of biomass and biomass wastes in supercritical water. Following a systematic process design methodology, thermodynamic property models and thermoeconomic process models for hydrolysis, salt separation, gasification and the separation of CH4, CO2, H2 and H2O at high pressure are developed and validated with experimental data. Different strategies for an integrated separation of the crude product, heat supply and energy recovery are elaborated and assembled in a general superstructure. The influence of the process design on the performance is discussed for some representative scenarios that highlight the key aspects of the design. Based on this work, a thermo-economic optimisation will allow for determining the most promising options for the polygeneration of fuel and power depending on the available technology, catalyst lifetime, substrate type and plant scale. © The Royal Society of Chemistry 2011. Source

Ivanov I.P.,University of Liege | Ivanov I.P.,RAS Sobolev Institute of Mathematics | Karlovets D.V.,Tomsk Polytechnic University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

Vortex electrons - freely propagating electrons whose wave functions have helical wave fronts - could become a novel tool in the physics of electromagnetic radiation. They carry a nonzero intrinsic orbital angular momentum (OAM) ℓ with respect to the propagation axis and, for ℓâ‰1, a large OAM-induced magnetic moment μ≈ℓμ B (μB is the Bohr magneton), which influences the radiation of electromagnetic waves. Here, we consider in detail the OAM-induced effects caused by such electrons in two forms of polarization radiation, namely, in Cherenkov radiation and transition radiation. Thanks to the large ℓ, we can neglect quantum or spin-induced effects, which are of the order of ω/Ee 1, but retain the magnetic moment contribution ℓaω/Ee1, which makes the quasiclassical approach to polarization radiation applicable. We discuss the magnetic moment contribution to polarization radiation, which has never been experimentally observed, and study how its visibility depends on the kinematical parameters and the medium permittivity. In particular, it is shown that this contribution can, in principle, be detected in azimuthally nonsymmetrical problems, for example when vortex electrons obliquely cross a metallic screen (transition radiation) or move near it (diffraction radiation). We predict a left-right angular asymmetry of the transition radiation (in the plane where the charge radiation distributions would stay symmetric), which appears due to an effective interference between the charge radiation field and the magnetic moment contribution. Numerical values of this asymmetry for vortex electrons with Ee=300 keV and ℓ=100-1000 are 0.1%-1%, and we argue that this effect could be detected with existing technology. The finite conductivity of the target and frequency dispersion play crucial roles in these predictions. © 2013 American Physical Society. Source

Ivanov I.P.,University of Liege | Ivanov I.P.,RAS Sobolev Institute of Mathematics | Karlovets D.V.,Tomsk Polytechnic University
Physical Review Letters | Year: 2013

Electromagnetic radiation can be emitted not only by particle charges but also by magnetic moments and higher electric and magnetic multipoles. However, experimental proofs of this fundamental fact are extremely scarce. In particular, the magnetic moment contribution has never been observed in any form of polarization radiation. Here, we propose to detect it using vortex electrons carrying large orbital angular momentum ℓ. The relative contribution of the orbital angular momentum-induced magnetic moment, ℓâ.,ω/E e, becomes much larger than the spin-induced contribution â.,ω/Ee, and it can be observed experimentally. As a particular example, we consider transition radiation from vortex electrons obliquely incident on an interface between a vacuum and a dispersive medium, in which the magnetic moment contribution manifests itself via a left-right angular asymmetry. For electrons with Ee=300 keV and ℓ=100-1000, we predict an asymmetry of the order of 0.1%-1%, which could be measured with existing technology. Thus, vortex electrons emerge as a new tool in the physics of electromagnetic radiation. © 2013 American Physical Society. Source

Boneh D.,Stanford University | Boyen X.,University of Liege
Journal of Cryptology | Year: 2011

We construct two efficient Identity-Based Encryption (IBE) systems that admit selective-identity security reductions without random oracles in groups equipped with a bilinear map. Selective-identity secure IBE is a slightly weaker security model than the standard security model for IBE. In this model the adversary must commit ahead of time to the identity that it intends to attack, whereas in an adaptive-identity attack the adversary is allowed to choose this identity adaptively. Our first system-BB 1-is based on the well studied decisional bilinear Diffie-Hellman assumption, and extends naturally to systems with hierarchical identities, or HIBE. Our second system-BB 2-is based on a stronger assumption which we call the Bilinear Diffie-Hellman Inversion assumption and provides another approach to building IBE systems. Our first system, BB 1, is very versatile and well suited for practical applications: the basic hierarchical construction can be efficiently secured against chosen-ciphertext attacks, and further extended to support efficient non-interactive threshold decryption, among others, all without using random oracles. Both systems, BB 1 and BB 2, can be modified generically to provide "full" IBE security (i.e., against adaptive-identity attacks), either using random oracles, or in the standard model at the expense of a non-polynomial but easy-to-compensate security reduction. © 2010 International Association for Cryptologic Research. Source

In Cambodia, the interactions between large-scale land investment and land titling gathered particular momentum in 2012-13, when the government initiated an unprecedented upland land titling programme in an attempt to address land tenure insecurity where large-scale land investment overlaps with land appropriated by peasants. This paper is based on a spatially explicit ethnography of land rights conducted in the Samlaut district of north-west Cambodia - a former Khmer Rouge resistance stronghold - in a context where the enclosures are both incomplete and entangled with post-war, socially embedded land tenure systems. We discuss how this new pattern of fragmentation affects the prevailing dynamics of agrarian change. We argue that it has introduced new forms of exclusion and a generalized perception of land tenure uncertainty that is managed by peasants through the actualization of hybrid land tenure arrangements borrowing from state rules and local consensus. In contrast with common expectations about land formalization, the process reinforces the patterns of social differentiation initiated by land rent capture practices of early migrants and pushes more vulnerable peasants into seeking wage labour and resorting to job migration. © 2016 John Wiley & Sons Ltd. Source

Zanolli Z.,Catholic University of Louvain | Zanolli Z.,University of Liege | Leghrib R.,Rovira i Virgili University | Felten A.,University of Namur | And 3 more authors.
ACS Nano | Year: 2011

The sensing properties of carbon nanotubes (CNTs) decorated with gold nanoparticles have been investigated by means of combined theoretical and experimental approaches. On one hand, first-principles and nonequilibrium Greens functions techniques give access to the microscopic features of the sensing mechanisms in individual nanotubes, such as electronic charge transfers and quantum conductances. On the other hand, drop coating deposition of carbon nanotubes decorated with gold nanoparticles onto sensor substrates and their characterization in the detection of pollutants such as NO2, CO, and C6H6 provide insight into the sensing ability of nanotube mats. Using the present combined approaches, the improvement in the detection of some specific gases (NO2 and CO) using Au-functionalized nanotubes is explained. However, for other gases such as C6H6, the Au nanoparticles do not seem to play a crucial role in the sensing process when compared with pristine CNTs functionalized with oxygen plasma. Indeed, these different situations can be explained by identifying the relationship between the change of resistance (macroscopic feature) and the shift of the Fermi level (microscopic feature) after gas adsorption. The understanding of the sensing ability at the atomic level opens the way to design new gas sensors and to tune their selectivity by predicting the nature of the metal that is the most appropriate to detect specific molecular species. © 2011 American Chemical Society. Source

Dey S.S.,Georgia Institute of Technology | Louveaux Q.,University of Liege
Mathematics of Operations Research | Year: 2011

A simple relaxation consisting of two rows of a simplex tableau is a mixed-integer set with two equations, two free integer variables, and nonnegative continuous variables. Recently, Andersen et al. and Cornuéjols and Margot showed that the facetdefining inequalities of this set are either split cuts or intersection cuts obtained from lattice-free triangles and quadrilaterals. From an example given by Cook et al. it is known that one particular class of facet-defining triangle inequality does not have finite split rank. In this paper we show that all other facet-defining triangle and quadrilateral inequalities have finite split rank. © 2011 INFORMS. Source

Denoel V.,University of Liege | Detournay E.,University of Minnesota | Detournay E.,CSIRO
International Journal of Solids and Structures | Year: 2011

The formulation of the constrained elastica problem proposed in this paper is predicated on two key concepts: first, the deformed elastica is described by means of the distance from the conduit axis; second, the problem is formulated in terms of the Eulerian curvilinear coordinate of the conduit rather than the natural curvilinear coordinate of the elastica. This approach is further implemented within a segmentation algorithm, which transforms the global constrained elastica problem into a sequence of analogous auxiliary problems that result from dividing the conduit and the elastica into segments limited by contacts. Each auxiliary segment entails solving a segment of elastica subject to isoperimetric constraints corresponding to the assumed positions of the segment ends along the conduit. This new formulation resolves in one stroke a series of issues that afflict the classical Lagrangian approach: (i) the contact detection is reduced to checking whether a threshold on the distance function is violated, (ii) the isoperimetric conditions are transformed into regular boundary conditions, instead of being treated as external integral constraints, (iii) the method yields a well-conditioned set of equations that does not degenerate with decreasing flexural rigidity of the elastica and/or decreasing clearance between the conduit and the elastica. © 2010 Elsevier Ltd. All rights reserved. Source

Bruggi M.,Polytechnic of Milan | Duysinx P.,University of Liege
Structural and Multidisciplinary Optimization | Year: 2012

The paper deals with a formulation for the topology optimization of elastic structures that aims at minimizing the structural weight subject to compliance and local stress constraints. The global constraint provides the expected stiffness to the optimal design while a selected set of local enforcements require feasibility with respect to the assigned strength of material. The Drucker-Prager failure criterion is implemented to handle materials with either equal or unequal behavior in tension and compression. A suitable relaxation of the equivalent stress measure is implemented to overcome the difficulties related to the singularity problem. Numerical examples are presented to discuss the features of the achieved optimal designs along with performances of the adopted procedure. Comparisons with pure compliance-based or pure stress-based strategies are also provided to point out differences arising in the optimal design with respect to conventional approaches, depending on the assumed material behavior. © 2012 Springer-Verlag. Source

Scheen A.J.,University of Liege
Postgraduate medicine | Year: 2013

Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) are oral incretin-based glucose-lowering agents with proven efficacy and safety in the management of type 2 diabetes mellitus (T2DM). In addition, preclinical data and mechanistic studies suggest a possible additional non-glycemic beneficial action on blood vessels and the heart, via both glucagon-like peptide-1-dependent and glucagon-like peptide-1-independent effects. As a matter of fact, DPP-4 inhibitors improve several cardiovascular risk factors: they improve glucose control (mainly by reducing the risk of postprandial hyperglycemia) and are weight neutral; may lower blood pressure somewhat; improve postprandial (and even fasting) lipemia; reduce inflammatory markers; diminish oxidative stress; improve endothelial function; and reduce platelet aggregation in patients with T2DM. In addition, positive effects on the myocardium have been described in patients with ischemic heart disease. Results of post hoc analyses of phase 2/3 controlled trials suggest a possible cardioprotective effect with a trend (sometimes significant) toward lower incidence of major cardiovascular events with sitagliptin, vildagliptin, saxagliptin, linagliptin, or alogliptin compared with placebo or other active glucose-lowering agents. However, the definite relationship between DPP-4 inhibition and better cardiovascular outcomes remains to be proven. Major prospective clinical trials involving various DPP-4 inhibitors with predefined cardiovascular outcomes are under way in patients with T2DM and a high-risk cardiovascular profile: the Sitagliptin Cardiovascular Outcome Study (TECOS) on sitagliptin, the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients With Diabetes Mellitus-Thrombolysis in Myocardial Infarction (SAVOR-TIMI) 53 trial on saxagliptin, the Cardiovascular Outcomes Study of Alogliptin in Subjects With Type 2 Diabetes and Acute Coronary Syndrome (EXAMINE) trial on alogliptin, and the Cardiovascular Outcome Study of Linagliptin Versus Glimepiride in Patients With Type 2 Diabetes (CAROLINA) on linagliptin. If these trials confirm that a DPP-4 inhibitor can reduce the cardiovascular burden of T2DM, it would be major progress that would dramatically influence the management of the disease. Source

Fagel N.,University of Liege | Mattielli N.,Free University of Colombia
Paleoceanography | Year: 2011

Bulk mineralogy, Sm, Nd and Pb elemental and isotopic compositions of the clay-size fraction of Holocene sediments were analyzed in three deep North Atlantic cores to trace the particle provenance. The aims of the present paper are to identify the origin of the particles driven by deep currents and to reconstruct deep circulation changes over the Holocene in the North Atlantic. The three cores are retrieved in fracture zones; two of them are located in the Island Basin along the gyre of North Atlantic Deep Water, and the third core is located off the present deep circulation gyre in the Labrador Sea. Whereas sedimentary supplies in the Labrador Sea were constantly derived from proximal sources, the geochemical mixing trends in the Iceland Basin samples indicate pronounced changes in the relative contribution of continental margin inputs over the past 6 kyr. Supplies from western European margin that sharply increased at 6 kyr were progressively diluted by a larger contribution of Scandinavian margins over the last 3 kyr. Changes in composition of the particles imply significant reorganization of paleocirculation of the deep North Atlantic components in the eastern basins: mainly reorganizations for both Iceland-Scotland Overflow Water and Norwegian Sea Overflow Water. Moreover the unusual Pb isotopic composition of the oldest sediments from the southern Iceland Basin indicates that distal supplies from Greenland margin were driven into the Iceland Basin, supporting a deep connection between Labrador Sea and Iceland Basin through the Charlie Gibbs Fracture Zone prior the Holocene Transition period. Copyright 2011 by the American Geophysical Union. Source

Louis R.,University of Liege
Revue Medicale de Liege | Year: 2011

Dyspnea is an extremely common symptom in medicine and in cardio-pulmonary medicine in particular. In most of the cases dyspnea reflects an unbalance between the ventilatory demand and the possibility of the thoracic and lung mechanics. Through to a simple clinical case describing an early stage of lung fibrosis we review the main causes and the differential diagnoses of dyspnea, and provide means of grading it through validated assessment scales. Source

During the Middle to Upper Paleolithic transition, a technocomplex known as the Lincombian- Ranisian-Jerzmanowician (LRJ), characterized by the presence of leaf-points made from blades, was found across the north-western European plain from Wales to Poland. Given the rarity and paucity of these assemblages, often mixed with other industries in collections from ancient excavations, many scholars have questioned the relevance of the definition of such a technocomplex. Nonetheless, based on technological and typological as well as chronological and geographic considerations, a precise study of available data shows that the LRJ cannot be considered as a facies of another technocomplex (Aurignacian, Szeletian or Bohunician). Identification of the LRJ also allows questions generally related to the 'transitional industries' to be tackled, such as their relation to either the last Neanderthals or the first European Homo sapiens sapiens and whether this complex is best explained as an independent development or as the result of acculturation. Given available data, the LRJ appears more likely to have been authored by Neanderthals, and is unlikely to be the result of acculturation processes. © 2011 Taylor & Francis. Source

Ceccopieri F.A.,University of Liege
European Physical Journal C | Year: 2016

By using a recently obtained set of Lambda fracture functions, we present predictions for Lambda production in the target fragmentation region of semi-inclusive deep inelastic scattering in CLAS@12 GeV kinematics, supplemented with a conservative error estimate. We discuss a number of observables sensitive to the assumptions of the underlying theory and many of the assumptions of the proposed phenomenological model. © 2016, The Author(s). Source

Stevens V.M.,CNRS Mechanical Adaptation and Evolution | Stevens V.M.,University of Liege | Turlure C.,CNRS Mechanical Adaptation and Evolution | Baguette M.,CNRS Mechanical Adaptation and Evolution
Biological Reviews | Year: 2010

Dispersal has recently gained much attention because of its crucial role in the conservation and evolution of species facing major environmental changes such as habitat loss and fragmentation, climate change, and their interactions. Butterflies have long been recognized as ideal model systems for the study of dispersal and a huge amount of data on their ability to disperse has been collected under various conditions. However, no single 'best' method seems to exist leading to the co-occurrence of various approaches to study butterfly mobility, and therefore a high heterogeneity among data on dispersal across this group. Accordingly, we here reviewed the knowledge accumulated on dispersal and mobility in butterflies, to detect general patterns. This meta-analysis specifically addressed two questions. Firstly, do the various methods provide a congruent picture of how dispersal ability is distributed across species? Secondly, is dispersal species-specific? Five sources of data were analysed: multisite mark-recapture experiments, genetic studies, experimental assessments, expert opinions, and transect surveys. We accounted for potential biases due to variation in genetic markers, sample sizes, spatial scales or the level of habitat fragmentation. We showed that the various dispersal estimates generally converged, and that the relative dispersal ability of species could reliably be predicted from their relative vagrancy (records of butterflies outside their normal habitat). Expert opinions gave much less reliable estimates of realized dispersal but instead reflected migration propensity of butterflies. Within-species comparisons showed that genetic estimates were relatively invariable, while other dispersal estimates were highly variable. This latter point questions dispersal as a species-specific, invariant trait. © 2010 Cambridge Philosophical Society. Source

Gabay O.,U.S. National Institutes of Health | Oppenheimer H.,Hebrew University of Jerusalem | Meir H.,Hebrew University of Jerusalem | Zaal K.,U.S. National Institutes of Health | And 2 more authors.
Annals of the Rheumatic Diseases | Year: 2012

Objective: A growing body of evidence indicates that the protein deacetylase, SirT1, affects chondrocyte biology and survival. This report aims to evaluate in vivo attributes of SirT1 in cartilage biology of 129/J murine strains. Methods: Heterozygous haploinsufficient (SirT1 +/-) and wild-type (WT; SirT1 +/+) 129/J mice aged 1 or 9 months were systematically compared for musculoskeletal features, scored for osteoarthritis (OA) severity, and monitored for chondrocyte apoptosis in articular cartilage. Sections of femorotibial joints were stained for type II collagen and aggrecan. Protein extracts from articular chondrocytes were isolated and immunoblotted for SirT1 and active caspase 3. Results: Phenotypic observations show that, at 1 month of age, SirT1 +/- mice were smaller than WT and showed a significant decrease in full-length SirT1 (FLSirT1; 110 kDa) protein levels. Levels of FLSirT1 were further decreased in both strains at 9 months. Immunoblot assays for 9-month-old strains revealed the presence of the inactive cleaved SirT1 variant (75 SirT1; 75 kDa) in WT mice, which was undetected in age-matched SirT1 +/- mice. Nine-month-old SirT1 +/- mice also showed increased OA and increased levels of apoptosis compared with age-matched WT mice. Conclusion: The data suggest that the presence of 75 SirT1 may prolong viability of articular chondrocytes in adult (9-month-old) mice. Source

Anselme P.,University of Liege
Behavioural Processes | Year: 2013

Invertebrates have been studied at biochemical, ecological, and behavioural levels, but current knowledge about the impact that learning may have on behaviour is rather sparse. The present study aimed to examine the sensitivity of isolated rough woodlice (Porcellio scaber, Latreille, 1804) to the tactile novelty of their environment. A simple way to test this issue was to refer to the place preference paradigm, traditionally used in vertebrates. In Experiment 1, woodlice were placed in a compartment for 30. min in order to assess their ability to develop habituation in the absence of reward. In Experiment 2, woodlice were exposed to a compartment for 20. min (habituation phase) and were then given free choice between that compartment and a novel compartment for 2. min (preference phase). Depending on test conditions, rewards (humidity and/or shelter) were present or absent in the familiar compartment. The familiar and novel compartments differed with respect to the texture of the floor. In Experiment 3, the floor texture was the same in the two compartments in order to control for a novelty effect. The main results indicate that woodlice exhibited increased locomotion time, increased distance travelled, and increased speed in the novel compartment compared to the familiar compartment. There was no preference for either compartment when the floor textures of both were identical. © 2012 Elsevier B.V. Source

Scheen A.J.,The Interdisciplinary Center | Scheen A.J.,University of Liege
Clinical Pharmacokinetics | Year: 2015

The prevalence of chronic kidney disease (CKD) of stages 3–5 (glomerular filtration rate [GFR] <60 mL/min) is about 25–30 % in patients with type 2 diabetes mellitus (T2DM). While most oral antidiabetic agents have limitations in patients with CKD, incretin-based therapies are increasingly used for the management of T2DM. This review analyses (1) the influence of CKD on the pharmacokinetics of dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists; and (2) the efficacy/safety profile of these agents in clinical practice when prescribed in patients with both T2DM and CKD. Most DPP-4 inhibitors (sitagliptin, vildagliptin, saxagliptin, alogliptin) are predominantly excreted by the kidneys. Thereby, pharmacokinetic studies showed that total exposure to the drug is increased in proportion to the decline of GFR, leading to recommendations for appropriate dose reductions according to the severity of CKD. In these conditions, clinical studies reported a good efficacy and safety profile in patients with CKD. In contrast, linagliptin is eliminated by a predominantly hepatobiliary route. As a pharmacokinetic study showed only minimal influence of decreased GFR on total exposure, no dose adjustment of linagliptin is required in the case of CKD. The experience with GLP-1 receptor agonists in patients with CKD is more limited. Exenatide is eliminated by renal mechanisms and should not be given in patients with severe CKD. Liraglutide is not eliminated by the kidney, but it should be used with caution because of the limited experience in patients with CKD. Only limited pharmacokinetic data are also available for lixisenatide, exenatide long-acting release (LAR) and other once-weekly GLP-1 receptor agonists in current development. Several case reports of acute renal failure have been described with GLP-1 receptor agonists, probably triggered by dehydration resulting from gastrointestinal adverse events. However, increasing GLP-1 may also exert favourable renal effects that could contribute to reducing the risk of diabetic nephropathy. In conclusion, the already large reassuring experience with DPP-4 inhibitors in patients with CKD offers new opportunities to the clinician, whereas more caution is required with GLP-1 receptor agonists because of the limited experience in this population. © 2014, Springer International Publishing Switzerland. Source

Lixisenatide (Lyxumia®) is a new agonist of Glucagon- Like Peptide-1 (GLP-1) receptors that is indicated in the treatment of type 2 diabetes, in one single subcutaneous daily injection of 20 μg. It exerts an incretin effect by stimulating insulin secretion after a meal while inhibiting glucagon secretion, both in a glucose-dependent manner, which limits the risk of hypoglycaemia. In addition, it slows down gastric emptying after a meal, which contributes to reduce postprandial hyperglycaemia, especially after breakfast. Lixisenatide is currently reimbursed in Belgium after failure of a dual therapy with metformin and a sulfonylurea but also in combination with a basal insulin (with or without oral antidiabetic drugs). The latter interesting combination should tackle fasting glycaemia with basal insulin (after appropriate dose titration) and postprandial hyperglycaemia with the GLP-1 receptor agonist in a complementary manner. The consequence is a further improvement of glycated haemoglobin (HbA1c) varying between 0.3 and 0.9 % in various studies comparing lixisenatide versus placebo. As other compounds of the class, lixisenatide induces a small weight reduction, which contrasts with the weight gain commonly observed with other antidiabetic medications (including insulin). Further studies should demonstrate the effects of lixisenatide on vascular complications and overall prognosis of patients with type 2 diabetes. Source

Hyaluronic acid, or hyaluronan, is a polymer made of the repetition of a unique disaccharidic unit, D-glucuronic acid and D-N-acetylglucosamine, that can reach a molecular mass of 107 daltons. This primitive polymer has emerged as a remarkable extracellular matrix component by its viscoelastic properties, its hygroscopic capacities and the diversity of cell processes it controls. Identified in all vertebrate tissues, more than 50% of acid hyaluronic of the organism is present in skin. Having no protein core, its synthesis is performed through a unique process, depending on enzymatic activity of hyaluronan synthases acting at the internal face of the plasmatic membrane and extruding the nascent polymer to the extracellular medium. This polymer constitutes a scaffold on which a large number of sulfated proteoglycans, up to one hundred, can be linked. These supramolecular structures of considerable size are able to entrap large amounts of water and ions to provide tissues with hydration and turgescence. Hyaluronic acid is recognized by cell membrane receptors, notably CD44 which is the best known. Interaction of hyaluronic acid with its receptors triggers several intracellular signaling pathways regulating proliferation, migration and differentiation. Cell response is largely influenced by the size of the polymer and by that of the fragments generated upon degradation by hyaluronidases or free radicals. Hyaluronic acid is metabolically very active, as, for example, its half-life in skin is less than one day. Detected in epidermis where it could play a role in the control of proliferation and differentiation of basal cells, it is however prominent in dermis in association with versican. The remarkable physicochemical properties of hyaluronic acid as well as the diversity of biological processes it controls largely surpass the primitive character of this polymer. © 2010 Elsevier Masson SAS. Tous droits réservés. Source

Le Bouquin J.-B.,CNRS Grenoble Institute for Particle Astrophysics and Cosmology Laboratory | Absil O.,University of Liege
Astronomy and Astrophysics | Year: 2012

Aims. We explore the sensitivity and completeness of long baseline interferometric observations for detecting unknown, faint companions around bright unresolved stars. Methods. We derive a linear expression for the closure phase signature of a faint companion in the high contrast regime (≤.1), and provide a quantitative estimation of the detection efficiency for the currently offered four-telescope configurations at the Very Large Telescope Interferometer. The results are compared to the performances provided by linear and Y-shaped interferometric configurations in order to identify the ideal array. Results. We find that all configurations have a similar efficiency in discovering companions wider than 10 mas. Assuming a closure phase accuracy of 0.25 deg that is typical of state-of-the-art instruments, we predict a median dynamic range of up to six magnitudes when stacking observations obtained at five different hour angles. Conclusions. Surveying bright stars to search for faint companions can be considered as an ideal filler programme for modern interferometric facilities because that places few constraints on the choice of the interferometric configuration. © 2012 ESO. Source

Denoel M.,University of Liege | Ficetola G.F.,University of Milan Bicocca | Ficetola G.F.,CNRS Alpine Ecology Laboratory
Journal of Animal Ecology | Year: 2014

Heterochrony, the change in the rate or timing of development between ancestors and their descendants, plays a major role in evolution. When heterochrony produces polymorphisms, it offers the possibility to test hypotheses that could explain its success across environments. Amphibians are particularly suitable to exploring these questions because they express complex life cycles (i.e. metamorphosis) that have been disrupted by heterochronic processes (paedomorphosis: retention of larval traits in adults). The large phenotypic variation across populations suggests that more complex processes than expected are operating, but they remain to be investigated through multivariate analyses over a large range of natural populations across time. In this study, we compared the likelihood of multiple potential environmental determinants of heterochrony. We gathered data on the proportion of paedomorphic and metamorphic palmate newts (Lissotriton helveticus) across more than 150 populations during 10 years and used an information-theoretic approach to compare the support of multiple potential processes. Six environmental processes jointly explained the proportion of paedomorphs in populations: predation, water availability, dispersal limitation, aquatic breathing, terrestrial habitat suitability and antipredator refuges. Analyses of variation across space and time supported models based on the advantage of paedomorphosis in favourable aquatic habitats. Paedomorphs were favoured in deep ponds, in conditions favourable to aquatic breathing (high oxygen content), with lack of fish and surrounded by suitable terrestrial habitat. Metamorphs were favoured by banks allowing easy dispersal. These results indicate that heterochrony relies on complex processes involving multiple ecological variables and exemplifies why heterochronic patterns occur in contrasted environments. On the other hand, the fast selection of alternative morphs shows that metamorphosis and paedomorphosis developmental modes could be easily disrupted in natural populations. © 2014 British Ecological Society. Source

Capa R.L.,University of Liege | Bouquet C.A.,University of Poitiers | Dreher J.-C.,University of Lyon | Dufour A.,University of Strasbourg
Cortex | Year: 2013

Motivation is often thought to interact consciously with executive control, although recent studies have indicated that motivation can also be unconscious. To date, however, the effects of unconscious motivation on high-order executive control functions have not been explored. Only a few studies using subliminal stimuli (i.e., those not related to motivation, such as an arrow to prime a response) have reported short-lived effects on high-order executive control functions. Here, building on research on unconscious motivation, in which a behavior of perseverance is induced to attain a goal, we hypothesized that subliminal motivation can have long-lasting effects on executive control processes. We investigated the impact of unconscious/conscious monetary reward incentives on evoked potentials and neural activity dynamics during cued task-switching performance. Participants performed long runs of task-switching. At the beginning of each run, a reward (50cents or 1 cent) was displayed, either subliminally or supraliminally. Participants earned the reward contingent upon their correct responses to each trial of the run. A higher percentage of runs was achieved with higher (conscious and unconscious) than lower rewards, indicating that unconscious high rewards have long-lasting behavioral effects. Event-related potential (ERP) results indicated that unconscious and conscious rewards influenced preparatory effort in task preparation, as suggested by a greater fronto-central contingent negative variation (CNV) starting at cue-onset. However, a greater parietal P3 associated with better reaction times (RTs) was observed only under conditions of conscious high reward, suggesting a larger amount of working memory invested during task performance. Together, these results indicate that unconscious and conscious motivations are similar at early stages of task-switching preparation but differ during task performance. © 2012 Elsevier Ltd. Source

Schmitz R.,Free University of Colombia | Dehon H.,University of Liege | Peigneux P.,Free University of Colombia
Cortex | Year: 2013

Aging is associated with higher propensity to false memories and decreased retrieval of previously studied items. When young adults (YA) perform on a lateralized version of the Deese-Roediger-McDermott (DRM) paradigm, the right cerebral hemisphere (RH) is more sensitive than the left (LH) to false memories, suggesting hemispheric imbalance in the cerebral mechanisms supporting semantic and episodic memory processes. Since cerebral asymmetries tend to be reduced with age, we surmised that behavioral asymmetries in the generation of false memories would be diminished with aging. To probe this hypothesis, a lateralized version of the DRM paradigm was administered to healthy older adults (OA) and YA. During the encoding phase, lists of semantically associated words were memorized. During the retrieval session, targets (previously seen words), lures (LU) (never seen strongly semantically related words) and distracters (never seen, unrelated words) were briefly displayed either in the left or right visual fields, thus primarily stimulating the RH or LH, respectively. Participants had to decide whether the word was previously studied (Old/New), but also whether they had a strong episodic recollection (Remember) or a mere feeling of familiarity (Know) about Old words. In line with our predictions, false memories were globally higher in OA than YA, and vivid false recollections (i.e., Remember responses) were higher when LU were presented in the RH in YA, but not in OA. Additionally, we found significant correlations between YA participants' Familiarity scores and leftward attentional bias as previously evidenced using a visuospatial landmark task (Schmitz and Peigneux, 2011), an effect not present in OA. This result is in line with the hypothesis of an interplay between attentional resources allocated to visuospatial and memory processes, suggesting a memory pseudoneglect phenomenon that would be altered with aging. © 2012 Elsevier Ltd. Source

Bautista M.A.,Western Michigan University | Ballance C.P.,Auburn University | Quinet P.,University of Mons | Quinet P.,University of Liege
Astrophysical Journal Letters | Year: 2010

We present new atomic data (radiative transitions rates and collision strengths) from large-scale calculations and a non-LTE spectral model for Fe III. This model is in very good agreement with observed astronomical emission spectra, in contrast with previous models that yield large discrepancies in observations. The present atomic computations employ a combination of atomic physics methods, e.g., relativistic Hartree-Fock, the Thomas-Fermi-Dirac potential, and Dirac-Fock computation of A-values and the R-matrix with intermediate coupling frame transformation and the Dirac R-matrix. We study advantages and shortcomings of each method. It is found that the Dirac R-matrix collision strengths yield excellent agreement with observations, much improved over previously available models. By contrast, the transformation of the LS-coupling R-matrix fails to yield accurate effective collision strengths at around 104 K, despite using very large configuration expansions, due to the limited treatment of spin-orbit effects in the near-threshold resonances of the collision strengths. The present work demonstrates that accurate atomic data for low-ionization iron-peak species are now within reach. © 2010. The American Astronomical Society. Source

Gatinel D.,Rothschild | Houbrechts Y.,University of Liege
Journal of Cataract and Refractive Surgery | Year: 2013

Purpose: To assess the differences in optical performance of 9 multifocal IOLs using the same optical bench and to propose a possible comparison for surgeons. Setting: Rothschild Foundation, Paris, France. Design: Experimental study. Methods: Nine IOLs (Acrysof Restor +3.0 diopter [D] SN6AD1, Acrysof Restor +4.0 D SN60D3, Acrysof aspheric monofocal SN60WF, Acri.Lisa 366D, Finevision Micro F, Tecnis ZM900, and Rezoom, Diffractiva Diff-s, and Lentis Mplus +3.0 D) were tested using the same optical bench that complies with International Organization for Standardization standard 11979 requirements. The through-focus modulation transfer functions (MTFs) were compared, and the image of the United States Air Force (USAF) target was taken while each IOL was at far, intermediate, and near focal points. Results: The through-focus MTF of the trifocal IOL showed a peak in the intermediate range that was not present with monofocal and bifocal IOLs. The USAF target images showed similar resolution with all IOLs for far focal points. Diffractive IOLs showed better resolution for near focal points, and the only sharp image in the intermediate range was obtained using the trifocal IOL. Conclusion: There was a significant difference in the degree of near, intermediate, and distance quality of the image with the various types of multifocal IOLs in vitro. Intermediate vision was more prominent with the trifocal IOL. Financial Disclosure: Dr. Gatinel has a proprietary interest in the optical frame used (Patent WO2011092169 [A1] 2011-08-04). Dr. Houbrechts has no financial or proprietary interest in any material or method mentioned. © 2013 ASCRS and ESCRS. Published by Elsevier Inc. Source

Ivanov I.P.,University of Liege | Ivanov I.P.,RAS Sobolev Institute of Mathematics
Journal of High Energy Physics | Year: 2010

We continue our analysis of the general N-Higgs-doublet model and focus of the Higgs potential description in the space of gauge orbits. We develop a geometric technique that allows us to study the global minimum of the potential without explicitly finding its position. We discuss symmetry patterns of the NHDM potential, and illustrate the general discussion with various specific variants of the three-Higgs-doublet model. © SISSA 2010. Source

Bruyneel F.,Catholic University of Louvain | Dive G.,University of Liege | Marchand-Brynaert J.,Catholic University of Louvain
Organic and Biomolecular Chemistry | Year: 2012

Oxidative cross-coupling reactions of substituted o-aminophenols were catalyzed by a commercial laccase to produce non-symmetrically substituted phenoxazinones for the first time. Identification by 1H-, 13C- and 31P-NMR, and by HPLC-PDA and HPLC-MS/MS of exclusively two kinds of substituted phenoxazinones out of four potential heterocyclic frameworks was confirmed by a DFT study. The redox-properties of the substrates, their relative rates of conversion and the rigid docking of selected substrates led to a revisited mechanistic pathway for phenoxazinones biosynthesis. Our suggestions concern both the first formal two-electron oxidation by laccase and the first intermolecular 1,4-conjugated addition which secures the observed regioselectivity. © 2012 The Royal Society of Chemistry. Source

Gommes C.J.,University of Liege
American Journal of Physics | Year: 2010

Although water rockets are widely used to illustrate first year physics principles, accurate measurements show that they outperform the usual textbook analysis at the beginning of the thrust phase. This paper gives a more thorough analysis of this problem. It is shown that the air expansion in the rocket is accompanied by water vapor condensation, which provides an extra thrust; the downward acceleration of water within the rocket also contributes to the thrust, an effect that is negligible in other types of rockets; the apparent gravity resulting from the acceleration of the rocket contributes as much to water ejection as does the pressure difference between the inside and outside of the rocket; and the water flow is transient, which precludes the use of Bernoulli's equation. Although none of these effects is negligible, they mostly cancel each other, and the overall accuracy of the analysis is only marginally improved. There remains a difference between theory and experiment with water rockets. © 2010 American Association of Physics Teachers. Source

Stancu F.,University of Liege
Journal of Physics G: Nuclear and Particle Physics | Year: 2010

In this exploratory study the spectrum of tetraquarks of type cc̄ss̄ is calculated within a simple quark model with chromomagnetic interaction and effective quark masses extracted from meson and baryon spectra. It is tempting to see if this spectrum can accommodate the resonance Y(4140), observed by the CDF Collaboration, but not yet confirmed. The results seem to favor the JPC = 1++ sector where the coupling to the VV channel is nearly as small as that of X(3872), when described as a cc̄qq̄ tetraquark. This suggests that Y(4140) could possibly be the strange partner of X(3872) in a tetraquark interpretation. However, the sector JPC = 0++ cannot entirely be excluded. This work questions the practice of extracting effective quark masses containing spinindependent contributions, from mesons and baryons, to be used in multiquark systems as well. © 2010 IOP Publishing Ltd. Source

Mauroy A.,University of California at Santa Barbara | Sepulchre R.J.,University of Liege
IEEE Transactions on Automatic Control | Year: 2013

We consider a continuum of phase oscillators on the circle interacting through an impulsive instantaneous coupling. In contrast with previous studies on related pulse-coupledmodels, the stability results obtained in the continuum limit are global. For the nonlinear transport equation governing the evolution of the oscillators, we propose (under technical assumptions) a global Lyapunov function which is induced by a total variation distance between quantile densities. The monotone time evolution of the Lyapunov function completely characterizes the dichotomic behavior of the oscillators: either the oscillators converge in finite time to a synchronous state or they asymptotically converge to an asynchronous state uniformly spread on the circle. The results of the present paper apply to popular phase oscillators models (e.g., the well-known leaky integrate-and-fire model) and show a strong parallel between the analysis of finite and infinite populations. In addition, they provide a novel approach for the (global) analysis of pulse-coupled oscillators. © 2012 IEEE. Source

Bennamoun L.,University of Liege
Drying Technology | Year: 2013

Photovoltaic (PV) cells have not been sufficiently used in drying processes in the past, particularly for solar drying, due to their high price and low efficiency. This is now changing due to the important scientific and technological recent developments in the PV field. An increase in the number of published scientific works related to the integration of PV cells is clearly visible. It is revealed that PV cells are integrated in drying systems for two essential reasons. The first relates to their use as a part of the solar collector (generally solar air collector), which permits an improvement of their low efficiency. As a result, and in most of the studied cases, the total solar collector efficiency has reached 70%. The second reason relates to the recycling of the electrical energy consumed by other drying system components such as fans. The recycled electrical energy was directly used for instant energy consumption or stored in batteries. The main application of PV cells is their use in direct- and indirect-type forced convection dryers, generally for food and herb drying. In a study case, an economic analysis has shown that payback is dependent on the ratio of the PV cell surface to the total solar collector surface, with the possibility of an optimum payback in less than one year. In another study case, an additional heat pump significantly improved the performance of the photovoltaic-thermal (PV/T) solar dryer, reaching an efficiency of 70%. A proper design of solar drying plays an important role in attaining optimum results. In this case, particular care is given to the design of solar dryers with a detailed presentation of the influence of the different parameters such as the surface of the PV cell, geographical location, and materials used. For most of the presented systems, efficiency is calculated after application of the heat and mass balance for each solar dryer compound. © 2013 Copyright Taylor and Francis Group, LLC. Source

Magne J.,French Institute of Health and Medical Research | Pibarot P.,University of Quebec | Sengupta P.P.,Mount Sinai School of Medicine | Donal E.,University of Rennes 1 | And 3 more authors.
JACC: Cardiovascular Imaging | Year: 2015

Pulmonary hypertension (PH) is a classic pathophysiological consequence of left-sided valvular heart disease (VHD). However, as opposed to other forms of PH, there are relatively few published data on the prevalence, impact on outcome, and management of PH with VHD. The objective of this paper is to present a systematic review of PH in patients with VHD. PH is found in 15% to 60% of patients with VHD and is more frequent among symptomatic patients. PH is associated with higher risk of cardiac events under conservative management, during valve replacement or repair procedures, and even following successful corrective procedures. In addition to its usefulness in assessing the presence and severity of VHD, Doppler echocardiography is a key tool in diagnosis of PH and assessment of its repercussion on right ventricular function. Assessment of pulmonary arterial pressure during exercise stress echocardiography may provide additional prognostic information beyond resting evaluation. Cardiac magnetic resonance is also useful for assessing right ventricular geometry and function, which provide additional prognostic information in patients with VHD and PH. © 2015 by the American College of Cardiology Foundation. Source

Bernier G.,University of Liege
Journal of Experimental Botany | Year: 2013

My favourite flowering image shows a section in a shoot apical meristem of Sinapis alba undertaking the very first step of its transition to flowering. This step is the activation of the SaSOC1 gene, the Sinapis orthologue of Arabidopsis SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1), in a few central cells of the meristem. Hidden behind this picture is my long quest of physiological signals controlling flowering. Milestones of this story are briefly recounted here and this gives me an opportunity to raise a number of questions about the nature and function of florigen. © The Author [2011]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights reserved. Source

Debout G.D.G.,Roosevelt University | Doucet J.-L.,University of Liege | Hardy O.J.,Roosevelt University
Heredity | Year: 2011

African rainforests have undergone major distribution range shifts during the Quaternary, but few studies have investigated their impact on the genetic diversity of plant species and we lack knowledge on the extent of gene flow to predict how plant species can cope with such environmental changes. Analysis of the spatial genetic structure (SGS) of a species is an effective method to determine major directions of the demographic history of its populations and to estimate the extent of gene dispersal. This study characterises the SGS of an African tropical timber tree species, Distemonanthus benthamianus, at various spatial scales in Cameroon and Gabon. Displaying a large continuous distribution in the Lower Guinea domain, this is a model species to detect signs of past population fragmentation and recolonization, and to estimate the extent of gene dispersal. Ten microsatellite loci were used to genotype 295 adult trees sampled from eight populations. Three clearly differentiated gene pools were resolved at this regional scale and could be linked to the biogeographical history of the region, rather than to physical barriers to gene flow. A comparison with the distribution of gene pools observed for two other tree species living in the same region invalidates the basic assumption that all species share the same Quaternary refuges and recolonization pathways. In four populations, significant and similar patterns of SGS were detected. Indirect estimates of gene dispersal distances (sigma) obtained for three populations ranged from 400 to 1200 m, whereas neighbourhood size estimates ranged from 50 to 110. © 2011 Macmillan Publishers Limited All rights reserved. Source

Charlier B.,University of Liege
American Mineralogist | Year: 2015

The onset of immiscibility in ferrobasaltic systems has been the subject of much research recently. The compositional space of the two-liquid field and the maximum temperature of the binodal surface have been investigated experimentally, but results from static and centrifuge experiments are controversial. In the article by Hou and Veksler (2015, May-June issue) entitled "Experimental confirmation of high-temperature silicate liquid immiscibility in multicomponent ferrobasaltic systems," the authors present experimental evidence for immiscibility between silica- and iron-rich melts at 1150-1200 °C, which are significantly higher to previous studies (ca. 1000-1025 °C). These results have important implications for potential largescale differentiation of magmas by liquid unmixing and for the formation of both Fe-Ti-P-rich melts and rhyolites. © Walter de Gruyter Berlin/Boston 2015. Source

Sanchez C.,University of Liege
Arthritis and rheumatism | Year: 2012

Recent data have shown that abnormal subchondral bone remodeling plays an important role in osteoarthritis (OA) onset and progression, and it was suggested that abnormal mechanical pressure applied to the articulation was responsible for these metabolic changes. This study was undertaken to evaluate the effects of cyclic compression on osteoblasts from OA subchondral bone. Osteoblasts were isolated from sclerotic and nonsclerotic areas of human OA subchondral bone. After 28 days, the osteoblasts were surrounded by an abundant extracellular matrix and formed a resistant membrane, which was submitted to cyclic compression (1 MPa at 1 Hz) for 4 hours. Gene expression was evaluated by reverse transcription-polymerase chain reaction. Protein production in culture supernatants was quantified by enzyme-linked immunosorbent assay or visualized by immunohistochemistry. Compression increased the expression of genes coding for interleukin-6 (IL-6), cyclooxygenase 2, RANKL, fibroblast growth factor 2, IL-8, matrix metalloproteinase 3 (MMP-3), MMP-9, and MMP-13 but reduced the expression of osteoprotegerin in osteoblasts in both sclerotic and nonsclerotic areas. Colα1(I) and MMP-2 were not significantly affected by mechanical stimuli. Nonsclerotic osteoblasts were significantly more sensitive to compression than sclerotic ones, but after compression, differences in messenger RNA levels between nonsclerotic and sclerotic osteoblasts were largely reduced or even abolished. Under basal conditions, sclerotic osteoblasts expressed similar levels of α5, αv, β1, and β3 integrins and CD44 as nonsclerotic osteoblasts but 30% less connexin 43, an important mechanoreceptor. Genes involved in subchondral bone sclerosis are mechanosensitive. After compression, nonsclerotic and sclerotic osteoblasts expressed a similar phenotype, suggesting that compression could be responsible for the phenotype changes in OA subchondral osteoblasts. Copyright © 2012 by the American College of Rheumatology. Source

Djani H.,Algerian Center de Developpement des Techniques Avancees | Hermet P.,Charles Gerhardt Institute | Ghosez P.,University of Liege
Journal of Physical Chemistry C | Year: 2014

The structural, dielectric, dynamical, elastic, piezoelectric, and nonlinear optical (second-order susceptibility and Pockels tensors) properties of Bi2WO6 in its P21ab ferroelectric ground state are determined using density functional theory. The calculation of infrared and Raman spectra allowed us to clarify the assignment of experimental phonon modes. The calculation of the elastic constants confirms the elastic stability of the crystal and allows us to estimate the Young and shear moduli of polycrystalline samples. The piezoelectric constants have significant intrinsic values comparable to those of prototypical ABO3 ferroelectrics. The electro-optic response is strongly dominated by the ionic contribution of transverse optic modes, yielding a sizable Pockels coefficients around 9 pm/V along the polar direction. © 2014 American Chemical Society. Source

A Derjaguin-Broekhoff-de Boer analysis of adsorption and desorption in SBA-15 mesoporous silica is presented, using realistic geometrical models that account for the pore corrugation in these materials. The model parameters are derived from independent electron tomography and small-angle scattering characterization. A geometrical characteristic of the pore that is found to be important for adsorption is the corrugation length, l C, which describes the longitudinal size of the geometrical defects along a given pore. Capillary bridges are possible only for large values of l C. The results are explained in terms of two spinodal and two equilibrium pressures, characterizing the wide and the narrow sections of the pores. Simplified analytical expressions are obtained, which provide necessary conditions for bridge formation and for cavitation in terms of the radii of the narrow and wide sections of the pores, as well as of l C. Quite generally, the results show that the deviation of the pore shape from that of ideal cylinders is key to understanding adsorption and desorption in corrugated mesopores, notably in SBA-15. © 2012 American Chemical Society. Source

Scheid B.,Free University of Colombia | Dorbolo S.,University of Liege | Arriaga L.R.,University Paris - Sud | Rio E.,University Paris - Sud
Physical Review Letters | Year: 2012

An antibubble is a spherical air film that is immersed in a surfactant mixture and drains under the action of hydrostatic pressure. A dynamical model of this film is proposed that accounts for the surface shear viscosity effects in the case of purely viscous interfaces, which applies for surfactants whose adsorption rate is much larger than advection rate and at a concentration much above the critical micelle concentration. Our model shows that the lifetime of the antibubbles in this case increases with surface shear viscosity, denoted ε, whose value is measured independently, all in agreement with experimental measurements. We also found that the critical thickness, h c, at film rupture due to van der Waals interactions slightly depends on the surface shear viscosity, namely hc1/6. © 2012 American Physical Society. Source

Lebon G.,University of Liege | Jou D.,Autonomous University of Barcelona
European Physical Journal H | Year: 2015

This paper gives a historical account of the early years (1953–1983) of extended irreversible thermodynamics (EIT). The salient features of this formalism are to upgrade the thermodynamic fluxes of mass, momentum, energy, and others, to the status of independent variables, and to explore the consistency between generalized transport equations and a generalized version of the second law of thermodynamics. This requires going beyond classical irreversible thermodynamics by redefining entropy and entropy flux. EIT provides deeper foundations, closer relations with microscopic formalisms, a wider spectrum of applications, and a more exciting conceptual appeal to non-equilibrium thermodynamics. We first recall the historical contributions by Maxwell, Cattaneo, and Grad on generalized transport equations. A thermodynamic theory wide enough to cope with such transport equations was independently proposed between 1953 and 1983 by several authors, each emphasizing different kinds of problems. In 1983, the first international meeting on this theory took place in Bellaterra (Barcelona). It provided the opportunity for the various authors to meet together for the first time and to discuss the common points and the specific differences of their previous formulations. From then on, a large amount of applications and theoretical confirmations have emerged. From the historical point of view, the emergence of EIT has been an opportunity to revisit the foundations and to open new avenues in thermodynamics, one of the most classical and well consolidated physical theories. © 2014, EDP Sciences and Springer-Verlag Berlin Heidelberg. Source

Vigeolas H.,University of Liege | Huhn D.H.,University of Zurich | Geigenberger P.,Ludwig Maximilians University of Munich
Plant Physiology | Year: 2011

Nonsymbiotic hemoglobins are ubiquitously expressed in plants and divided into two different classes based on gene expression pattern and oxygen-binding properties. Most of the published research has been on the function of class 1 hemoglobins. To investigate the role of class 2 hemoglobins, transgenic Arabidopsis (Arabidopsis thaliana) plants were generated overexpressing Arabidopsis hemoglobin-2 (AHb2) under the control of a seed-specific promoter. Overexpression of AHb2 led to a 40% increase in the total fatty acid content of developing and mature seeds in three subsequent generations. This was mainly due to an increase in the polyunsaturated C18:2 (ω-6) linoleic and C18:3 (ω-3) α-linolenic acids. Moreover, AHb2 overexpression led to an increase in the C18:2/C18:1 and C18:3/C18:2 ratios as well as in the C18:3 content in mol % of total fatty acids and in the unsaturation/saturation index of total seed lipids. The increase in fatty acid content was mainly due to a stimulation of the rate of triacylglycerol synthesis, which was attributable to a 3-fold higher energy state and a 2-fold higher sucrose content of the seeds. Under low external oxygen, AHb2 overexpression maintained an up to 5-fold higher energy state and prevented fermentation. This is consistent with AHb2 overexpression results in improved oxygen availability within developing seeds. In contrast to this, overexpression of class 1 hemoglobin did not lead to any significant increase in the metabolic performance of the seeds. These results provide evidence for a specific function of class 2 hemoglobin in seed oil production and in promoting the accumulation of polyunsaturated fatty acids by facilitating oxygen supply in developing seeds. © 2011 American Society of Plant Biologists. Source

Viatour P.,Stanford University | Viatour P.,University of Liege | Sage J.,Stanford University
DMM Disease Models and Mechanisms | Year: 2011

The retinoblastoma (RB) tumor suppressor belongs to a cellular pathway that plays a crucial role in restricting the G1-S transition of the cell cycle in response to a large number of extracellular and intracellular cues. Research in the last decade has highlighted the complexity of regulatory networks that ensure proper cell cycle progression, and has also identified multiple cellular functions beyond cell cycle regulation for RB and its two family members, p107 and p130. Here we review some of the recent evidence pointing to a role of RB as a molecular adaptor at the crossroads of multiple pathways, ensuring cellular homeostasis in different contexts. In particular, we discuss the pro- and anti-tumorigenic roles of RB during the early stages of cancer, as well as the importance of the RB pathway in stem cells and cell fate decisions. Source

Karsisiotis A.I.,University of Essex | Damblon C.F.,University of Liege | Roberts G.C.K.,University of Leicester
Metallomics | Year: 2014

Metallo-β-lactamases are important as a major source of resistance of pathogenic bacteria to the widely used β-lactam antibiotics. They show considerable diversity in terms of sequence and are grouped into three subclasses, B1, B2 and B3, which share a common overall fold. In each case the active enzyme has binding sites for two zinc ions in close proximity, although the amino-acid residues which coordinate the metals vary from one subclass to another. In subclasses B1 and B3, there has been controversy about whether both zinc ions are required for activity, but the most recent evidence indicates that there is positive cooperativity in zinc binding and that the catalytically relevant species is the di-zinc enzyme. Subclass B2 enzymes, on the other hand, are active in the mono-zinc state and are inhibited by the binding of a second zinc ion. Evidence for the importance of the zinc ions in substrate binding has come from structures of product complexes which indicate that the β-lactam core binds to subclass B1 and B3 enzymes in a rather consistent fashion, interactions with the zinc ions being centrally important. The zinc ions play key roles in the catalytic mechanism, including facilitating nucleophilic attack on the amide carbonyl by the zinc-bound hydroxide ion, stabilising the anionic tetrahedral intermediate and coordinating the departing amine nitrogen. © 2014 the Partner Organisations. Source

Melamed A.,Imperial College London | Laydon D.J.,Imperial College London | Gillet N.A.,Imperial College London | Gillet N.A.,University of Liege | And 3 more authors.
PLoS Pathogens | Year: 2013

The regulation of proviral latency is a central problem in retrovirology. We postulate that the genomic integration site of human T lymphotropic virus type 1 (HTLV-1) determines the pattern of expression of the provirus, which in turn determines the abundance and pathogenic potential of infected T cell clones in vivo. We recently developed a high-throughput method for the genome-wide amplification, identification and quantification of proviral integration sites. Here, we used this protocol to test two hypotheses. First, that binding sites for transcription factors and chromatin remodelling factors in the genome flanking the proviral integration site of HTLV-1 are associated with integration targeting, spontaneous proviral expression, and in vivo clonal abundance. Second, that the transcriptional orientation of the HTLV-1 provirus relative to that of the nearest host gene determines spontaneous proviral expression and in vivo clonal abundance. Integration targeting was strongly associated with the presence of a binding site for specific host transcription factors, especially STAT1 and p53. The presence of the chromatin remodelling factors BRG1 and INI1 and certain host transcription factors either upstream or downstream of the provirus was associated respectively with silencing or spontaneous expression of the provirus. Cells expressing HTLV-1 Tax protein were significantly more frequent in clones of low abundance in vivo. We conclude that transcriptional interference and chromatin remodelling are critical determinants of proviral latency in natural HTLV-1 infection. © 2013 Melamed et al. Source

Majerus S.,University of Liege | D'Argembeau A.,Fonds de la Recherche Scientifique FNRS
Journal of Memory and Language | Year: 2011

Many studies suggest that long-term lexical-semantic knowledge is an important determinant of verbal short-term memory (STM) performance. This study explored the impact of emotional valence on word immediate serial recall as a further lexico-semantic long-term memory (LTM) effect on STM. This effect is particularly interesting for the study of STM-LTM interactions since emotional words not only activate specific lexico-semantic LTM features but also capture attentional resources, and hence allow for the study of both LTM and attentional factors on STM tasks. In Experiments 1 and 2, we observed a robust effect of emotional valence on pure list recall in both young and elderly adults, with higher recall performance for emotional lists as opposed to neutral lists, as predicted by increased LTM support for emotional words. In Experiments 3 and 4 however, using mixed lists, it was the lists containing a minority of emotional words which led to higher recall performance over lists containing a majority of emotional words. This was predicted by a weak version of the attentional capture account. These data add new evidence to the theoretical position that LTM knowledge is a critical determinant of STM performance, with further, list type dependent intervention of attentional factors. © 2010 Elsevier Inc. Source

De Cock B.,Free University of Brussels | De Cock B.,University of Liege
Journal of Pragmatics | Year: 2011

This article focuses on the phenomenon of 1st person plural forms being used with hearer reference, e.g. a teacher saying to his/her students " We're going to be quiet now" in Spanish (a pro-drop language) and English (a non-pro-drop language), paying attention to both contrasts and similarities between them. The physical persons involved in interaction (speaker and hearer) are distinguished from the discursive roles (addresser and addressee). While coinciding by default, in some cases the interpretation of the 1st person plural forms shifts towards the addressee, thus triggering a hearer-dominant reading. On the one hand, this shift is argued to be not merely a matter of contextual interpretation, but to be triggered by linguistic elements, such as vocatives, interrogative speech acts and tense. On the other hand, the politeness judgment of this strategy is questioned in the light of various (im)politeness theories and a plea is made for taking into account the broader linguistic and non-linguistic context of the utterance. While the hearer-dominant reading occurs both in English and in Spanish, there appear to be differences as to the impact of the subject pronoun and the position of the strategy within the address system as a whole. © 2011 Elsevier B.V. Source

Van Angelen J.H.,University Utrecht | Lenaerts J.T.M.,University Utrecht | Van Den Broeke M.R.,University Utrecht | Fettweis X.,University of Liege | Van Meijgaard E.,Royal Netherlands Meteorological Institute
Geophysical Research Letters | Year: 2013

Mass loss from the two major ice sheets and their contribution to global sea level rise is accelerating. In Antarctica, mass loss is dominated by increased flow velocities of outlet glaciers, following the thinning or disintegration of coastal ice shelves into which they flow. In contrast, ∼55% of post-1992 Greenland ice sheet (GrIS) mass loss is accounted for by surface processes, notably increased meltwater runoff. A subtle process in the surface mass balance of the GrIS is the retention and refreezing of meltwater, currently preventing ∼40% of the meltwater to reach the ocean. Here we force a high-resolution atmosphere/snow model with a mid-range warming scenario (RCP4.5, 1970-2100), to show that rapid loss of firn pore space, by >50% at the end of the 21st century, quickly reduces this refreezing buffer. As a result, GrIS surface mass loss accelerates throughout the 21st century and its contribution to global sea level rise increases to 1.7 ±0.5 mm yr -1, more than four times the current value. © 2013 American Geophysical Union. All Rights Reserved. Source

Demory B.-O.,Massachusetts Institute of Technology | Gillon M.,University of Liege | Seager S.,Massachusetts Institute of Technology | Benneke B.,Massachusetts Institute of Technology | And 2 more authors.
Astrophysical Journal Letters | Year: 2012

We report on the detection of infrared light from the super-Earth 55Cnce, based on four occultations obtained with Warm Spitzer at 4.5 μm. Our data analysis consists of a two-part process. In a first step, we perform individual analyses of each data set and compare several baseline models to optimally account for the systematics affecting each light curve. We apply independent photometric correction techniques, including polynomial detrending and pixel mapping, that yield consistent results at the 1σ level. In a second step, we perform a global Markov Chain Monte Carlo analysis, including all four data sets that yield an occultation depth of 131 ± 28ppm, translating to a brightness temperature of 2360 ± 300 K in the IRAC 4.5 μm channel. This occultation depth suggests a low Bond albedo coupled to an inefficient heat transport from the planetary day side to the night side, or else possibly that the 4.5 μm observations probe atmospheric layers that are hotter than the maximum equilibrium temperature (i.e., a thermal inversion layer or a deep hot layer). The measured occultation phase and duration are consistent with a circular orbit and improves the 3σ upper limit on 55Cnce's orbital eccentricity from 0.25 to 0.06. © 2012. The American Astronomical Society. All rights reserved.. Source

Pissart A.,University of Liege
Permafrost and Periglacial Processes | Year: 2010

Based on observations in northern Québec and Belgium, the author infers that lithalsas in northern Québec are modern analogues of the enclosed and ramparted depressions that occur on the Hautes Fagnes plateau, Belgium. It is hypothesised that the growth of these lithalsas occurs not only by vertical heave associated with ice segregation within mineral material but also by lateral frost thrusting. © 2010 John Wiley & Sons, Ltd. Source

Otte M.,University of Liege
Quaternary International | Year: 2010

Bifacial technology can be by realized by different ways. A simplistic, often outmoded view of western European prehistory cannot be imposed on other regions. The so-called " Acheulean" from China is in fact included in the specific technologies made on pebbles, which dictate the shapes, on the exact contrary than real bifaces whose forms are built up from any raw material category. © 2009 Elsevier Ltd and INQUA. Source

Bonneville J.-F.,University of Liege
Frontiers of Hormone Research | Year: 2016

Magnetic Resonance Imaging (MRI) is currently considered a major keystone of the diagnosis of diseases of the hypothalamic-hypophyseal region. However, the relatively small size of the pituitary gland, its location deep at the skull base and the numerous physiological variants present in this area impede the precise assessment of the anatomical structures and, particularly, of the pituitary gland itself. The diagnosis of the often tiny lesions of this region - such as pituitary microadenomas - is then difficult if the MRI technology is not optimized and if potential artifacts and traps are not recognized. Advanced MRI technology can not only depict small lesions with greater reliability, but also help in the differential diagnosis of large tumors. In these, defining the presence or absence of invasion is a particularly important task. This review describes and illustrates the radiological diagnosis of the different tumors of the sellar region, from the common prolactinomas, nonfunctioning adenomas and Rathke's cleft cysts, to the less frequent and more difficult to detect corticotroph pituitary adenomas in Cushing's disease, and other neoplastic and nonneoplastic entities. Finally, some hints are given to facilitate the differential diagnosis of sellar lesions. © 2016 S. Karger AG, Basel. Source

Lozano C.,University of Navarra | Lumay G.,University of Liege | Zuriguel I.,University of Navarra | Hidalgo R.C.,University of Navarra | Garcimartin A.,University of Navarra
Physical Review Letters | Year: 2012

We present experimental and numerical results regarding the stability of arches against external vibrations. Two-dimensional strings of mutually stabilizing grains are geometrically analyzed and subsequently submitted to a periodic forcing at fixed frequency and increasing amplitude. The main factor that determines the granular arch resistance against vibrations is the maximum angle among those formed between any particle of the arch and its two neighbors: the higher the maximum angle is, the easier it is to break the arch. On the basis of an analysis of the forces, a simple explanation is given for this dependence. From this, interesting information can be extracted about the expected magnitudes of normal forces and friction coefficients of the particles composing the arches. © 2012 American Physical Society. Source

Kang J.,Yale University | Kugathasan S.,Emory University | Georges M.,University of Liege | Zhao H.,Yale University | Cho J.H.,Yale University
Human Molecular Genetics | Year: 2011

Genome-wide association studies have identified numerous loci demonstrating genome-wide significant association with Crohn's disease. However, when many single nucleotide polymorphisms (SNPs) have weak-to-moderate disease risks, genetic risk prediction models based only on those markers that pass the most stringent statistical significance testing threshold may be suboptimal. Haplotype-based predictive models may provide advantages over single-SNP approaches by facilitating detection of associations driven by cis-interactions among nearby SNPs. In addition, these approaches may be helpful in assaying non-genotyped, rare causal variants. In this study, we investigated the use of two-marker haplotypes for risk prediction in Crohn's disease and show that it leads to improved prediction accuracy compared with single-point analyses. With large numbers of predictors, traditional classification methods such as logistic regression and support vector machine approaches may be suboptimal. An alternative approach is to apply the risk-score method calculated as the number of risk haplotypes an individual carries, both within and across loci. We used the area under the curve (AUC) of the receiver operating curve to assess the performance of prediction models in large-scale genetic data, and observed that the prediction performance in the validation cohort continues to improve as thousands of haplotypes are included in the model, with the AUC reaching its plateau at 0.72 at ~7000 haplotypes, and begins to gradually decline after that point. In contrast, using the SNP as predictors, we only obtained maximum AUC of 0.65. Validation studies in independent cohorts further support improved prediction capacity with multi-marker, as opposed to single marker analyses. © The Author 2011. Published by Oxford University Press. All rights reserved. Source

Tian L.,Catholic University of Leuven | Humblet-Baron S.,Catholic University of Leuven | Humblet-Baron S.,University of Liege | Liston A.,Catholic University of Leuven
BioEssays | Year: 2012

The potential for self-reactive T cells to cause autoimmune disease is held in check by Foxp3 + regulatory T cells (Tregs), essential mediators of peripheral immunological tolerance. Tregs have the capacity to suppress multiple branches of the immune system, tightly controlling the different subsets of effector T cells across multiple different tissue environments. Recent genetic experiments have found mutations that disrupt specific Treg: effector T cell relationships, leading to the possibility that subsets of Tregs are required to suppress each subset of effector T cells. Here we review the environmental factors and mechanisms that allow Tregs to suppress specific subsets of effector T cells, and find that a parsimonious explanation of the genetic data can be made without invoking Treg subsets. Instead, Tregs show a functional and chemotactic plasticity based on microenvironmental influences that allows the common pool of cells to suppress multiple distinct immune responses. © 2012 WILEY Periodicals, Inc. Source

Fonseca Diaz N.,Technological University of Pereira | Fonseca Diaz N.,University of Liege
Applied Energy | Year: 2011

As a part of a commissioning study, the chilled ceiling system of a large commercial building located in Belgium is evaluated. A representative office has been instrumented and data on the chilled ceiling system operating in real conditions have been collected. The simulation of the whole system is performed by means of a transient thermal model of the building and its HVAC system. The model considers the hydronic panels as a transient-state finned heat exchanger connected to a simplified lumped transient model of the building. The behavior of the hydronic ceiling system and the interactions with its environment (walls, ventilated facade, internal loads and ventilation system) has been experimentally and numerically evaluated. Commissioning test results show that the influence of surfaces temperatures inside the room, especially the facade, is considerable. Then, it is clear that the hydronic ceiling system must be evaluated together with its designed environment and not as a separate HVAC equipment. © 2010 Elsevier Ltd. Source

Boudard A.,CEA Saclay Nuclear Research Center | Cugnon J.,University of Liege | David J.-C.,CEA Saclay Nuclear Research Center | Leray S.,CEA Saclay Nuclear Research Center | Mancusi D.,CEA Saclay Nuclear Research Center
Physical Review C - Nuclear Physics | Year: 2013

The new version (incl4.6) of the Liège intranuclear cascade (INC) model for the description of spallation reactions is presented in detail. Compared to the standard version (incl4.2), it incorporates several new features, the most important of which are: (i) the inclusion of cluster production through a dynamical phase space coalescence model, (ii) the Coulomb deflection for entering and outgoing charged particles, (iii) the improvement of the treatment of Pauli blocking and of soft collisions, (iv) the introduction of experimental threshold values for the emission of particles, (v) the improvement of pion dynamics, (vi) a detailed procedure for the treatment of light-cluster-induced reactions taking care of the effects of binding energy of the nucleons inside the incident cluster and of the possible fusion reaction at low energy. Performances of the new model concerning nucleon-induced reactions are illustrated by a comparison with experimental data covering total reaction cross sections, neutron, proton, pion, and composite double-differential cross-sections, neutron multiplicities, residue mass and charge distributions, and residue recoil velocity distributions. Whenever necessary, the incl4.6 model is coupled to the ABLA07 de-excitation model and the respective merits of the two models are then tentatively disentangled. Good agreement is generally obtained in the 200 MeV to 2 GeV range. Below 200 MeV and down to a few tens of MeV, the total reaction cross section is well reproduced and differential cross sections are reasonably well described. The model is also tested for light-ion induced reactions at low energy, below 100 MeV incident energy per nucleon. Beyond presenting the update of the incl4.2 model, attention has been paid to applications of the new model to three topics for which some particular aspects are discussed for the first time. The first topic is the production of clusters heavier than alpha particle. It is shown that the energy spectra of these produced clusters are consistent with coalescence. The second topic regards the longitudinal residue recoil velocity and its fluctuations. Excellent results are obtained for these quantities. It addition, it is shown that the distributions of these quantities display typical random-walk characteristics, at least for not-too-large mass losses. They are interpreted as a direct consequence of the independence of successive binary collisions occurring during the cascade process. The last topic concerns the total reaction cross section and the residue-production cross sections for low-energy incident light ions. It is shown that our new model can give a rather satisfactory account of these cross sections, offering so an alternative to fusion models and the advantage of a single model for the progressive change from fusion to pre-equilibrium mechanisms. © 2013 American Physical Society. Source

The main aim of this paper was to present some feeding recommendations, which, when applied on the farm, would increase nitrogen use by bovines and to give information as to how the effects of the nitrogen produced can be reduced. Ruminants have the ability to digest structural carbohydrates and to produce meat and milk proteins for human consumption. At the animal cells level, amino acids are essential for biological functions, mainly involving their maintenance and production. These amino acids are supplied by the intestinal digestion of microbial protein and feed protein that escapes microbial degradation in the rumen. Today, the efficiency of nitrogen utilization is typically low and highly variable in ruminants. Nitrogen excretion by ruminants mainly depends on the level of nitrogen intake and of the animal's productivity. Optimal N utilization may be achieved through an understanding of the key mechanisms involved in the control of N digestion and metabolism. These include the efficiency of N capture in the rumen and the protein degradation according to the type of diet and forage, the control of the rumen microorganisms involved in protein degradation and the proper formulation of the diet, avoiding feeding excess protein in relation to requirements. The dependence on energy supply in transferring feed nitrogen into milk and meat protein is strong both at the rumen and the cell levels of ruminants. The rumen metabolism is identified as the single most important factor contributing to the low level of efficient use of nitrogen in ruminants and partially depends on practical farming operations. Source

Bonfond B.,University of Liege
Journal of Geophysical Research: Space Physics | Year: 2010

The Io footprint (IFP) is the auroral signature of the electromagnetic interaction between Io and Jupiter's magnetosphere. It consists of several spots followed by an extended tail, which are located close to the feet of the magnetic field lines connecting Io to Jupiter. The size of the main spot is a controversial issue, and previously published values range from ∼400 to ∼8000 km. However, this question is crucial to understand the processes at play, since this quantity is expected to reflect the size of the interaction region at Io. The present study provides estimates of the size of the Io footprint on a much larger image sample than before, paying a particular attention to the differentiation of the spots and to their 3-D structure. The length of the Main Alfvén Wing (MAW) spot and the length of the trans-hemispheric electron beam (TEB) spot along the footpath are ∼850 km, while their width perpendicular to the footpath is <200 km. Larger lengths are sometimes observed, but these configurations may be attributed to the overlaps of the different spots. The spot lengths are larger than the projected diameter of Io along unperturbed magnetic field lines, which is consistent with recent simulations. The narrowness of the IFP will need to be carefully accounted for in future studies of its brightness. Additionally, the peak altitudes of the MAW and the TEB spot are as high as 900 and 700 km, respectively, which seem to confirm their different origins. Copyright 2010 by the American Geophysical Union. Source

Mottequin B.,University of Liege
Special Papers in Palaeontology | Year: 2010

A diverse Tournaisian (Carboniferous, Mississippian) brachiopod fauna has been recorded within the stratotype of the tempestite-dominated Hook Head Formation at Hook Head, County Wexford (south-east Ireland). The Hook Head Formation (335 m thick), which mainly consists of interbedded limestones of tempestite origin and shales, deposited on a shelf-ramp and yielded a rich invertebrate fauna (crinoids, bryozoans, corals, etc.). Thirty-three brachiopod species, of which one is new (Rugosochonetes sleemani), assigned to 29 genera, have been recognized. The brachiopod fauna is dominated by productides and spirebearers (athyridides, spiriferides, and spiriferinides) and shares strong similarities with those reported in Wales and southern Belgium (Namur-Dinant Basin), which derived from the same palaeogeographical context. © The Palaeontological Association. Source

Capitanescu F.,University of Liege
IEEE Transactions on Power Systems | Year: 2011

This paper proposes a two-step approach to evaluate reactive power reserves with respect to operating constraints and voltage stability for a set of postulated operating scenarios. The first step determines the minimum overall needed reactive power reserves of generators such that the system withstands, from a static viewpoint, any postulated scenario. This problem is formulated as a security constrained optimal power flow (SCOPF) which includes operating constraints relative to all postulated scenarios. Particular attention is paid to the techniques aimed to reduce the large size of the SCOPF problem. The second step determines additional reserves to ensure voltage stability of scenarios for which, when modeling dynamic system behavior, the reserves obtained by SCOPF are insufficient. These reserves are computed using a heuristic technique which relies on dynamic simulation. Numerical results on four test systems of 60, 118, 618, and 1203 buses support the interest of the approach. © 2006 IEEE. Source

Rizzoli R.,University of Geneva | Reginster J.-Y.,University of Liege
Expert Review of Clinical Pharmacology | Year: 2011

Treatments for postmenopausal osteoporosis are generally safe, but are linked to some rare serious adverse drug reactions, for which causality is not always certain. The bisphosphonates are associated with gastrointestinal effects, acute phase reactions, and musculoskeletal pain, and, more rarely, cases of atrial fibrillation, subtrochanteric fracture, osteonecrosis of the jaw, cutaneous hypersensitivity reactions and renal impairment. It is too soon for pharmacovigilance data on denosumab, but it has been associated with cutaneous effects and possibly osteonecrosis of the jaw (to date, only in metastatic cancer). The selective estrogen receptor modulators may induce hot flushes and leg cramps, and - more rarely - venous thromboembolism and stroke. Strontium ranelate is associated with headache, nausea and diarrhea, and, more rarely, cutaneous hypersensitivity reactions and venous thromboembolism, while teriparatide and parathyroid hormone(1-84) are associated with headache, nausea, dizziness and limb pain. The management of osteoporosis should entail weighing the probability of adverse reactions against the benefits of therapy - that is, reduction of fracture risk. © 2011 Expert Reviews Ltd. Source

Perelman S.,University of Liege | Serebrisky T.,The World Bank
Utilities Policy | Year: 2012

Relying on a unique dataset this paper uses Data Envelopment Analysis methods to compute an efficient production frontier for a representative sample of Latin American airports. Latin America has implemented a wide variety of private sector participation schemes in the airport sector since the late 90s. To assess whether privately operated airports had higher rates of total factor productivity growth than public airports we compute Malmquist indexes for the period 2000-2007. Results indicate that privately operated airports enjoyed higher rates of total factor productivity growth. © 2012 Elsevier Ltd. Source

Gommes C.J.,University of Liege | Gommes C.J.,Princeton University | Jiao Y.,Princeton University | Torquato S.,Princeton University
Physical Review Letters | Year: 2012

The degeneracy of two-phase disordered microstructures consistent with a specified correlation function is analyzed by mapping it to a ground-state degeneracy. We determine for the first time the associated density of states via a Monte Carlo algorithm. Our results are explained in terms of the roughness of an energy landscape, defined on a hypercubic configuration space. The use of a Hamming distance in this space enables us to define a roughness metric, which is calculated from the correlation function alone and related quantitatively to the structural degeneracy. This relation is validated for a wide variety of disordered structures. © 2012 American Physical Society. Source

Pire B.,Ecole Polytechnique - Palaiseau | Semenov-Tian-Shansky K.,University of Liege | Szymanowski L.,National Center for Nuclear Research
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

The associated production of a J/ψ and a π meson in antiproton-nucleon annihilation is studied in the framework of QCD collinear factorization. In this approach, a hard subprocess responsible for the production of the heavy quark-antiquark pair factorizes from soft hadronic matrix elements, such as the antiproton (nucleon) distribution amplitude and the nucleon-to-pion (antiproton-to-pion) transition distribution amplitude. This reaction mechanism should dominate the forward and backward kinematical regions, where the cross sections are expected to be measurable in the set-up of the P̄ANDA experiment at the GSI-FAIR facility. © 2013 Elsevier B.V. Source

Chabbert-Buffet N.,University Pierre and Marie Curie | Pintiaux A.,University of Liege | Bouchard P.,University Pierre and Marie Curie
Molecular and Cellular Endocrinology | Year: 2012

Selective progesterone receptor modulators (SPRMs) have been developed since the late 70s when mifepristone was first described. They act through nuclear progesterone receptors and can have agonist or mixed agonist antagonist actions depending on the cell and tissue. Mifepristone has unique major antagonist properties allowing its use for pregnancy termination. Ulipristal acetate has been marketed in 2009 for emergency contraception and has been recently approved for preoperative myoma treatment. Further perspectives for SPRMs use include long term estrogen free contraception, endometriosis treatment. However long term applications will be possible only after confirmation of endometrial safety. © 2012. Source

Jarmuszkiewicz W.,Adam Mickiewicz University | Woyda-Ploszczyca A.,Adam Mickiewicz University | Antos-Krzeminska N.,Adam Mickiewicz University | Sluse F.E.,University of Liege
Biochimica et Biophysica Acta - Bioenergetics | Year: 2010

Uncoupling proteins (UCPs) are members of the mitochondrial anion carrier protein family that are present in the mitochondrial inner membrane and mediate free fatty acid (FFA)-activated, purine nucleotide (PN)-inhibited proton conductance. Since 1999, the presence of UCPs has been demonstrated in some non-photosynthesising unicellular eukaryotes, including amoeboid and parasite protists, as well as in non-fermentative yeast and filamentous fungi. In the mitochondria of these organisms, UCP activity is revealed upon FFA-induced, PN-inhibited stimulation of resting respiration and a decrease in membrane potential, which are accompanied by a decrease in membranous ubiquinone (Q) reduction level. UCPs in unicellular eukaryotes are able to divert energy from oxidative phosphorylation and thus compete for a proton electrochemical gradient with ATP synthase. Our recent work indicates that membranous Q is a metabolic sensor that might utilise its redox state to release the PN inhibition of UCP-mediated mitochondrial uncoupling under conditions of phosphorylation and resting respiration. The action of reduced Q (QH2) could allow higher or complete activation of UCP. As this regulatory feature was demonstrated for microorganism UCPs (A. castellanii UCP), plant and mammalian UCP1 analogues, and UCP1 in brown adipose tissue, the process could involve all UCPs. Here, we discuss the functional connection and physiological role of UCP and alternative oxidase, two main energy-dissipating systems in the plant-type mitochondrial respiratory chain of unicellular eukaryotes, including the control of cellular energy balance as well as preventive action against the production of reactive oxygen species. © 2009 Elsevier B.V. Source

Gommes C.J.,University of Liege | Gommes C.J.,Catholic University of Leuven
Journal of Applied Crystallography | Year: 2013

Small-angle scattering of X-rays (SAXS) or neutrons is one of the few experimental methods currently available for the in situ analysis of phenomena in mesoporous materials at the mesoscopic scale. In the case of disordered mesoporous materials, however, the main difficulty of the method lies in the data analysis. A stochastic model is presented, which enables one to reconstruct the three-dimensional nanostructure of liquids confined in disordered mesopores starting from small-angle scattering data. This so-called plurigaussian model is a multi-phase generalization of clipped Gaussian random field models. Its potential is illustrated through the synchrotron SAXS analysis of a gel permeated with a critical nitrobenzene/hexane solution that is progressively cooled below its consolute temperature. The reconstruction brings to light a wetting transition whereby the nanostructure of the pore-filling liquids passes from wetting layers that uniformly cover the solid phase of the gel to plugs that locally occlude the pores. Using the plurigaussian model, the dewetting phenomenon is analyzed quantitatively at the nanometre scale in terms of changing specific interface areas, contact angle and specific length of the triple line. Copyright © International Union of Crystallography 2013. Source

Hatert F.,University of Liege | Ottolini L.,CNR Institute of Geosciences and Earth Resources | Schmid-Beurmann P.,Institute For Mineralogie
Contributions to Mineralogy and Petrology | Year: 2011

In order to assess the stability of the primary alluaudite + triphylite assemblage, we performed hydrothermal experiments between 400 and 800°C, starting from the LiNa2MnxFe3-x2+Fe3+(PO4)4 compositions (x = 1. 054, 1. 502, 1. 745) that represent the ideal compositions of the alluaudite + triphylite assemblages from the Kibingo (Rwanda), Hagendorf-Süd (Germany), and Buranga (Rwanda) pegmatites, respectively. The pressure was maintained at 1 kbar, and the oxygen fugacity was controlled by the Ni-NiO buffer. The results of these experiments show that the alluaudite + triphylite assemblage crystallizes at 400 and 500°C, while the association alluaudite + triphylite + marićite appears at 600 and 700°C. The limit between these two domains, at ca. 550°C, corresponds to the maximum temperature that can be reached by the alluaudite + triphylite assemblages in granitic pegmatites, because marićite has never been observed in such geological environments. At 800°C, the formation of the X-phase + triphylite assemblage indicates a strong reduction of the bulk composition, according to the reaction 0.5LiM2+PO4 (triphylite) + 3Na2M22+Fe3+(PO4)3 (alluaudite) + 1.5H2O = 4.5NaM2+PO4 (marićite) + Li0.5Na1.5M52+(PO4)4 (X-phase) + H3PO4 + 0.75O2 (M2+ = Fe2+, Mn). Secondary ion mass spectrometry (SIMS) was used at our knowledge for the first time to measure Li in all the Li-bearing phosphates. A specific methodological procedure was developed with the ion microprobe to get accurate Li2O data over a wide concentration range spanning from few ppm Li up to ~11 wt%. Li2O. Our SIMS analyses of the synthesized phosphates indicate that the Li contents of alluaudites, marićites, and X-phase increase progressively with temperature, while the Li content of triphylite-type phosphates decreases due to the Li → Na substitution. The Na-exchange equilibrium between triphylite-type phosphates and alluaudite is correlated with the temperature according to the equation: ln(xNaTri/xNaAll) = -7.0(7) 103/T + 5.4(9). This equation can be used to estimate the crystallization temperature of triphylite-alluaudite assemblages independently of the oxygen fugacity. © 2010 Springer-Verlag. Source

Scheen A.J.,University of Liege
Expert Opinion on Drug Metabolism and Toxicology | Year: 2014

Introduction: Patients with type 2 diabetes have an increased risk of chronic liver disease (CLD) such as non-alcoholic fatty liver disease and steatohepatitis and about one-third of cirrhotic patients have diabetes. However, the use of several antidiabetic agents may be a cause for concern in the case of hepatic impairment (HI). Areas covered: An extensive literature search was performed to analyze the influence of HI on the pharmacokinetics (PK) of glucose-lowering agents and the potential consequences for clinical practice as far as the efficacy/safety balance of their use in diabetic patients with CLD is concerned. Expert opinion: Almost no PK studies have been published regarding metformin, sulfonylureas, thiazolidinediones and α-glucosidase inhibitors in patients with HI. Only mild changes in PK of glinides, dipeptidyl peptidase-4 inhibitors and sodium glucose cotransporters type 2 inhibitors were observed in dedicated PK studies in patients with various degrees of HI, presumably without major clinical relevance although large clinical experience is lacking. Glucagon-like peptide-1 receptor agonists have a renal excretion rather than liver metabolism. Rare anecdotal case reports of hepatotoxicity have been described with various glucose-lowering agents contrasting with numerous reassuring data. Nevertheless, caution should be recommended, especially in patients with advanced cirrhosis, including with the use of metformin. © 2014 Informa UK, Ltd. Source

Boumal N.,Catholic University of Louvain | Mishra B.,Catholic University of Louvain | Absil P.-A.,University of Liege | Sepulchre R.,University of Cambridge
Journal of Machine Learning Research | Year: 2014

Optimization on manifolds is a rapidly developing branch of nonlinear optimization. Its focus is on problems where the smooth geometry of the search space can be leveraged to design effcient numerical algorithms. In particular, optimization on manifolds is well-suited to deal with rank and orthogonality constraints. Such structured constraints appear pervasively in machine learning applications, including low-rank matrix completion, sensor network localization, camera network registration, independent component analysis, metric learning, dimensionality reduction and so on. The Manopt toolbox, available at www.manopt.org, is a user-friendly, documented piece of software dedicated to simplify experimenting with state of the art Riemannian optimization algorithms. By dealing internally with most of the differential geometry, the package aims particularly at lowering the entrance barrier. © 2014 Nicolas Boumal. Source

Martin L.-A.,Institute of Cancer Research | Andre F.,University Paris - Sud | Andre F.,Institute Gustave Roussy | Campone M.,Institute Of Cancerologie Of Louest Rene Gauducheau | And 2 more authors.
Cancer Treatment Reviews | Year: 2013

Current therapeutic approaches for advanced breast cancer frequently target receptors mediating cell survival and proliferation, such as the estrogen receptor and/or progesterone receptor and human epidermal growth factor receptor-2. Although these approaches are effective for many patients, treatment resistance is common. Therefore, new treatment approaches are needed for patients with advanced breast cancer. Mammalian target of rapamycin is a highly conserved serine-threonine kinase that acts as a major signaling hub that integrates and synergizes with cellular proliferation, survival, and/or motility signals mediated by estrogen receptor, human epidermal growth factor receptor-2, and other receptor tyrosine kinases. Dysregulation of mammalian target of rapamycin signaling occurs in various tumor types, including breast cancer, and has been associated with cancer pathogenesis, disease progression, and treatment resistance. Recent clinical trials show that combined inhibition of mammalian target of rapamycin and estrogen receptor represents an effective strategy for treating hormone receptor-positive advanced breast cancer progressing on nonsteroidal aromatase inhibitor therapy, and data from ongoing trials combining mammalian target of rapamycin inhibition with human epidermal growth factor receptor-2-targeted therapy are awaited. This review focuses on the molecular rationale underlying strategies to enhance sensitivity to treatment in hormone receptor-positive and human epidermal growth factor receptor-2-positive advanced breast cancer, the clinical efficacy of such approaches, and future perspectives. © 2013. Source

Senn S.,CRP Sante | Gavini F.,I.R.I Servier | Magrez D.,I.R.I Servier | Scheen A.,University of Liege
Statistical Methods in Medical Research | Year: 2013

The example of the analysis of a collection of trials in diabetes consisting of a sparsely connected network of 10 treatments is used to make some points about approaches to analysis. In particular various graphical and tabular presentations, both of the network and of the results are provided and the connection to the literature of incomplete blocks is made. It is clear from this example that is inappropriate to treat the main effect of trial as random and the implications of this for analysis are discussed. It is also argued that the generalisation from a classic random-effect meta-analysis to one applied to a network usually involves strong assumptions about the variance components involved. Despite this, it is concluded that such an analysis can be a useful way of exploring a set of trials. © The Author(s) 2011 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav. Source

Terwagne D.,University of Liege | Bush J.W.M.,Massachusetts Institute of Technology
Nonlinearity | Year: 2011

We present the results of an experimental investigation of the acoustics and fluid dynamics of Tibetan singing bowls. Their acoustic behaviour is rationalized in terms of the related dynamics of standing bells and wine glasses. Striking or rubbing a fluid-filled bowl excites wall vibrations, and concomitant waves at the fluid surface. Acoustic excitation of the bowl's natural vibrational modes allows for a controlled study in which the evolution of the surface waves with increasing forcing amplitude is detailed. Particular attention is given to rationalizing the observed criteria for the onset of edge-induced Faraday waves and droplet generation via surface fracture. Our study indicates that drops may be levitated on the fluid surface, induced to bounce on or skip across the vibrating fluid surface. © 2011 IOP Publishing Ltd & London Mathematical Society. Source

Sierra D.A.,University of Liege | De Medeiros Varzielas I.,University of Basel
Journal of High Energy Physics | Year: 2014

In terms of its eigenvector decomposition, the neutrino mass matrix (in the basis where the charged lepton mass matrix is diagonal) can be understood as originating from a tribimaximal dominant structure with small deviations, as demanded by data. If neutrino masses originate from at least two different mechanisms, referred to as "hybrid neutrino masses", the experimentally observed structure naturally emerges provided one mechanism accounts for the dominant tribimaximal structure while the other is responsible for the deviations. We demonstrate the feasibility of this picture in a fairly model-independent way by using lepton-number-violating effective operators, whose structure we assume becomes dictated by an underlying A 4 flavor symmetry. We show that if a second mechanism is at work, the requirement of generating a reactor angle within its experimental range always fixes the solar and atmospheric angles in agreement with data, in contrast to the case where the deviations are induced by next-to-leading order effective operators. We prove this idea is viable by constructing an A 4-based ultraviolet completion, where the dominant tribimaximal structure arises from the type-I seesaw while the subleading contribution is determined by either type-II or type-III seesaw driven by a non-trivial A 4 singlet (minimal hybrid model). After finding general criteria, we identify all the ZN symmetries capable of producing such A ;bsubesub based minimal hybrid models. © 2014 The Author(s). Source

Englebert J.,University of Liege
Evolution Psychiatrique | Year: 2013

This paper addresses the issue of paranoiac hermeneutic (search for meaning and significance). As any human hermeneutics, this tendency to interpret the world includes a relational dimension as well as a bodily dimension. Three paradigms are proposed by the author to define this hermeneutics: (1) "the hazard does not exist"; (2) "a certainty that is yet to be proved" and (3) "the paranoiac is unable to turn to a third party". This theoretical and clinical study also discusses the paranoiac logic in individuals free of mental illness and seeks to determine how a psychological paranoiac functioning will be part of the psychotic register or not. The concepts of "loss of natural evidence" and "pathology of common sense" are those which are used to demonstrate that is in the social and relational dimensions that the problems of the paranoiac lie. The fundamental question regarding the status of reality and knowledge (and of its diffusion) is the dimension that causes the switch to psychosis. The hermeneutics of the relationship is empty for the paranoiac and his "knowledge" no longer meets the social rules which normally turn interpretation into opinion and not into delusion. © 2013 Elsevier Masson SAS. Source

Afshan S.,Imperial College London | Rossi B.,University of Liege | Gardner L.,Imperial College London
Journal of Constructional Steel Research | Year: 2013

This paper describes a material test programme carried out as part of an extensive study into the prediction of strength enhancements in cold-formed structural sections. The experiments cover a wide range of cross-section geometries - twelve Square Hollow Sections (SHS), five Rectangular Hollow Sections (RHS) and one Circular Hollow Section (CHS), and materials - austenitic (EN 1.4301, 1.4571 and 1.4404), ferritic (EN 1.4509 and 1.4003), duplex (EN 1.4462) and lean duplex (EN 1.4162) stainless steel and grade S355J2H carbon steel. The experimental techniques implemented, the generated data and the analysis methods employed are fully described. The results from the current test programme were combined with existing measured stress-strain data on cold-formed sections from the literature and following a consistent analysis of the combined data set, revised values for Young's modulus E and the Ramberg-Osgood material model parameters n, n′0.2,u and n′0.2,1.0 are recommended. A comparison between the recommended values and the codified values provided in AS/NZS 4673 (2001) [1], SEI/ASCE-8 (2002) [2] and EN 1993-1-4 (2006) [3] is also presented. The test results are also used in a companion paper Rossi et al. (submitted for publication) [4] for developing suitable predictive models to determine the strength enhancements in cold-formed structural sections that arise during the manufacturing processes. © 2012 Elsevier Ltd. All rights reserved. Source

Fettweis X.,University of Liege | Fettweis X.,University Utrecht | Tedesco M.,City College of New York | Van Den Broeke M.,University Utrecht | Ettema J.,University Utrecht
Cryosphere | Year: 2011

To study near-surface melt changes over the Greenland ice sheet (GrIS) since 1979, melt extent estimates from two regional climate models were compared with those obtained from spaceborne microwave brightness temperatures using two different remote sensing algorithms. The results from the two models were consistent with those obtained with the remote sensing algorithms at both daily and yearly time scales, encouraging the use of the models for analyzing melting trends before the satellite era (1958-1979), when forcing data is available. Differences between satellite-derived and model-simulated results still occur and are used here to identify (i) biases in the snow models (notably in the albedo parametrization, in the thickness of a snow layer, in the maximum liquid water content within the snowpack and in the snowfall impacting the bare ice appearance in summer) and (ii) limitations in the use of passive microwave data for snowmelt detection at the edge of the ice sheet due to mixed pixel effect (e.g., tundra or rock nearby the ice sheet). The results from models and spaceborne microwave sensors confirm a significant (p-value Combining double low line 0.01) increase in GrIS surface melting since 1979. The melt extent recorded over the last years (1998, 2003, 2005 and 2007) is unprecedented in the last 50 yr with the cumulated melt area in the 2000's being, on the average, twice that of the 1980's. © 2011 Author(s). Source

Sarlette A.,University of Liege | Raimond J.M.,Kastler-Brossel Laboratory | Brune M.,Kastler-Brossel Laboratory | Rouchon P.,MINES ParisTech
Physical Review Letters | Year: 2011

We propose an engineered reservoir inducing the relaxation of a cavity field towards nonclassical states. It is made up of two-level atoms crossing the cavity one at a time. Each atom-cavity interaction is first dispersive, then resonant, then dispersive again. The reservoir pointer states are those produced by an effective Kerr Hamiltonian acting on a coherent field. We thereby stabilize squeezed states and quantum superpositions of multiple coherent components in a cavity having a finite damping time. This robust decoherence protection method could be implemented in state-of-the-art experiments. © 2011 American Physical Society. Source

The pharmacological therapy of type 2 diabetes has become increasingly complex and the goals are now more diverse and, in general, more stringent. The glycaemic target (glycated haemoglobin or HbA1c) and the medications to be prescribed to reach it should be selected according to the individual characteristics of the patient and, if possible, in agreement with him/her. The most relevant criteria to be taken into account are the glucose-lowering efficacy, the risk of hypoglycaemia, the effect on body weight, the side effects and the costs. We summarize here the strategy proposed in the joint "position statement" published in 2012 by the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). We will more particularly focus our attention on the practical aspects useful for the clinician. Source

Aapro M.,IMO Clinique de Genolier | Osterborg A.,Karolinska Institutet | Gascon P.,University of Barcelona | Ludwig H.,Center for Oncology and Haematology | Beguin Y.,University of Liege
Annals of Oncology | Year: 2012

Background: Chronic diseases reduce the availability of iron for effective erythropoiesis. This review summarises clinical consequences of iron deficiency (ID) and anaemia in cancer patients, mechanisms how impaired iron homeostasis affects diagnosis and treatment of ID, and data from clinical trials evaluating i.v. iron with or without concomitant erythropoiesis-stimulating agents (ESAs). Design: Clinical trial reports were identified in PubMed and abstracts at relevant major congresses. Results: Reported prevalence of ID in cancer patients ranges from 32 to 60% and most iron-deficient patients are also anaemic. Randomised clinical trials have shown superior efficacy of i.v. iron over oral or no iron in reducing blood transfusions, increasing haemoglobin, and improving quality of life in ESA-treated anaemic cancer patients. Furthermore, i.v. iron without additional ESA should be evaluated as potential treatment in patients with chemotherapy-induced anaemia. At recommended doses, i.v. iron is well tolerated, particularly compared with oral iron. No serious drug-related adverse effects were seen during long-term use in renal disease and no effect on tumour growth has been observed in trials with anaemic cancer patients. Conclusions: Reliable diagnosis and treatment of ID are recommended key steps in modern cancer patient management to minimise impact on quality of life and performance status. © The Author 2012. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. Source

Bruls O.,University of Liege | Cardona A.,CONICET | Arnold M.,Martin Luther University of Halle Wittenberg
Mechanism and Machine Theory | Year: 2012

This paper studies a Lie group extension of the generalized-α time integration method for the simulation of flexible multibody systems. The equations of motion are formulated as an index-3 differential-algebraic equation (DAE) on a Lie group, with the advantage that rotation variables can be taken into account without the need of introducing any parameterization. The proposed integrator is designed to solve this equation directly on the Lie group without index reduction. The convergence of the method for DAEs is studied in detail and global second-order accuracy is proven for all solution components, i.e. for nodal translations, rotations and Lagrange multipliers. The convergence properties are confirmed by three benchmarks of rigid and flexible systems with large rotation amplitudes. The Lie group method is compared with a more classical updated Lagrangian method which is also formulated in a Lie group setting. The remarkable simplicity of the new algorithm opens interesting perspectives for real-time applications, model-based control and optimization of multibody systems. © 2011 Elsevier Ltd. All rights reserved. Source

Georges M.,University of Liege
Nature Genetics | Year: 2011

Follow-up studies of a Crohn's disease risk locus encompassing IRGM have revealed unexpected complexity. A new study shows that a synonymous variant in the IRGM coding region alters a binding site for miR-196 and modulates IRGM-dependent autophagy, adding to the list of possible mechanisms by which this locus influences disease risk. © 2011 Nature America, Inc. All rights reserved. Source

Mottet D.,University of Liege
Current cancer drug targets | Year: 2010

Judah Folkman was the first in 1971 to observe and report that cancer growth and dissemination were dependent on angiogenesis - the formation of new blood vessels from pre-existing vasculature. For almost 40 years, this concept has inspired generations of researchers to identify anti-angiogenic molecules that could be used therapeutically to stop blood vessels formation and starve tumors of nutrients and oxygen. Tumor angiogenesis requires complex cellular and molecular interactions between endothelial and cancer cells. In response to external stimuli such as hypoxia, cancer cells secrete pro-angiogenic factors into the extracellular matrix that activate the surrounding endothelial cells to proliferate, migrate and form new blood vessels. So, vascularization of malignant lesions depends on the expression of specific genes in both endothelial and tumor cells and accumulating evidences shows that several members of the histone deacetylase (HDAC) family play key roles in the regulation of these genes. Indeed, numerous in vitro and in vivo studies demonstrated that inhibitors of HDAC modulate angiogenic gene expression in both endothelial and cancer cells and disturb the delicate and complex balance between the collective action of pro-angiogenic factors and angiogenesis inhibitors. Thus, HDAC are currently recognized as promising targets for the development of anti-cancer drugs. This review is an effort to present and discuss the role, functions and mechanisms of action of HDAC during tumor-driven angiogenesis as well as a brief summary of the clinical status of the main HDAC inhibitors (HDACi) currently under development in cancer therapy. Source

Zamorano J.L.,University Hospital Ramon y Cajal | Gonzalez-Gomez A.,University Hospital Ramon y Cajal | Lancellotti P.,University of Liege
EuroIntervention | Year: 2014

Mitral regurgitation is a common valvular heart disease and its prevalence is expected to increase with population ageing. Percutaneous techniques for the treatment of mitral regurgitation are emerging as an alternative therapeutic option. However, the mitral valve is a complex structure, and a comprehensive understanding of the anatomy of the mitral valve apparatus and its surrounding structures is crucial for a correct selection of patients and the success of transcatheter mitral valve interventions. © Europa Digital & Publishing 2014. All rights reserved. Source

Lepot K.,University of Liege | Benzerara K.,CNRS Paris Institute of Global Physics | Philippot P.,CNRS Paris Institute of Global Physics
Earth and Planetary Science Letters | Year: 2011

Titanite-bearing microtubes in metabasalts have been interpreted as evidence for early microbial life thriving in the oceanic crust up to 3.5. Ga ago based on similarities with microtubular pitting occurring in modern volcanic glass. An alternative abiogenic origin as ambient inclusions trails (AITs) has been debated but textural evidence such as the absence of diagnostic terminal inclusions was used to discard this possibility. Here, we describe a variety of microtubes occurring in pyroclastic tuff of the 2.72. Ga Tumbiana Formation, Western Australia, some of which resemble titanite-filled microtubes reported in metamorphosed Archean pillow basalts. To assess the origin of the Tumbiana microtubes, we investigated their structure and chemistry and their root zone down to the sub-micrometer scale using a combination of Raman microspectroscopy, scanning electron microscopy (SEM), focused ion beam (FIB) milling and scanning transmission electron microscopy (STEM) coupled with energy dispersive X-ray spectrometry (EDXS). We report four types of microtubes. Type 1 comprises calcite microtubes. Type 2 comprises AITs showing terminal pyrite and trails with negative crystal shapes. Type 3 comprises titanite microtubes in chlorite displaying morphologies similar to those reported in ~. 3.5. Ga old Archean lavas. At the sub-micrometer scale, they display a dendritic structure. Depending on their localization, Type 3 microtubes have been divided in three main sub-types: i) Type 3A extends in pores filled by chloritized cement, ii) Type 3B occurs in pyroclasts, and iii) Type 3C overgrows and thus post-dates Type 2 AITs. Type 4 comprises titanite microtubes confined to quartz and calcite rims. Types 3 and 4 microtubes are terminated by sub-micrometric carbonaceous and/or mineral inclusions. Altogether, these features suggest that the Tumbiana titanite microtubes have formed as dendritic AITs associated with displacement of mineral and/or organic inclusions in pyroclasts and in surrounding void-filling cements during recrystallization. They are therefore unlikely to represent relics of the activity of early microbial life, rather abiotic features formed in the presence of organic matter during burial metamorphism. In that sense, they may represent some sort of indirect evidence for life. © 2011 Elsevier B.V. Source

Ivanov I.P.,University of Liege | Ivanov I.P.,RAS Sobolev Institute of Mathematics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

Photons carrying nonzero orbital angular momentum (twisted photons) are well-known in optics. Recently, using Compton backscattering to boost optical twisted photons to high energies was suggested. Twisted electrons in the intermediate energy range have also been produced recently. Thus, collisions involving energetic twisted particles seem to be feasible and represent a new tool in high-energy physics. Here we discuss some generic features of scattering processes involving twisted particles in the initial and/or final state. In order to avoid additional complications arising from nontrivial polarization states, we focus here on scalar fields only. We show that processes involving twisted particles allow one to perform a Fourier analysis of the plane-wave cross section with respect to the azimuthal angles of the initial particles. In addition, using twisted states, one can probe the autocorrelation function of the amplitude, which is inaccessible in the plane-wave collisions. Finally, we discuss prospects for experimental study of these effects. © 2011 American Physical Society. Source

Ivanov I.P.,University of Liege | Ivanov I.P.,RAS Sobolev Institute of Mathematics | Serbo V.G.,RAS Sobolev Institute of Mathematics
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

High-energy photons and other particles carrying nonzero orbital angular momentum (OAM) emerge as a new tool in high-energy physics. Recently, it was suggested to generate high-energy photons with nonzero OAM (twisted photons) by the Compton backscattering of twisted optical photons on relativistic electron beams. Twisted electrons in the intermediate energy range have also been demonstrated experimentally; twisted protons and other particles can, in principle, be created in a similar way. Collisions of energetic twisted states can offer a new look at particle properties and interactions. A theoretical description of twisted particle scattering developed previously treated them as pure Bessel states and ran into difficulty when describing the OAM of the final twisted particle at nonzero scattering angles. Here we develop further this formalism by incorporating two additional important features. First, we treat the initial OAM state as a wave packet of a finite transverse size rather than a pure Bessel state. This realistic assumption allows us to resolve the existing controversy between two theoretical analyses for nonforward scattering. Second, we describe the final twisted particle in terms of the orbital helicity: the OAM projection on its average direction of propagation rather than on the fixed reaction axis. Using this formalism, we determine to what extent the twisted state is transferred from the initial to final OAM particle in a generic scattering kinematics. As a particular application, we prove that in the Compton backscattering the orbital helicity of the final photon stays close to the OAM projection of the initial photon. © 2011 American Physical Society. Source

Wallemacq Q.,University of Liege
Advances in High Energy Physics | Year: 2014

We reinterpret the results of the direct searches for dark matter in terms of milli-interacting dark particles. The model reproduces the positive results from DAMA/LIBRA and CoGeNT and is consistent with the absence of signal in the XENON100, CDMS-II/Ge, and LUX detectors. Dark atoms, interacting with standard atoms through a kinetic mixing between photons and dark photons and a mass mixing of σ mesons with dark scalars, diffuse elastically in terrestrial matter where they deposit all their energy. Reaching underground detectors through gravity at thermal energies, they form bound states with nuclei of the active medium by radiative capture, which causes the emission of photons that produce the observed signals. The parameter space of the model is explored and regions reproducing the results at the 2σ level are obtained for each experiment. © 2014 Quentin Wallemacq. Source

Ciarcelluti P.,Web Institute of Physics | Wallemacq Q.,University of Liege
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We present new fast numerical simulations of cosmic microwave background and large scale structure in the case in which the cosmological dark matter is made entirely or partly made of mirror matter. We consider scalar adiabatic primordial perturbations at linear scales in a flat Universe. The speed of the simulations allows us for the first time to use Markov Chain Monte Carlo analyses to constrain the mirror parameters. A Universe with pure mirror matter can fit very well the observations, equivalently to the case of an admixture with cold dark matter. In both cases, the cosmological models estimate the presence of a consistent amount of mirror dark matter, 0.06≲Ωmirrorh2≲0.12. © 2013 The Authors. Source

Censier F.,University of Liege
Communications in agricultural and applied biological sciences | Year: 2012

The saddle gall midge, Haplodiplosis marginata (von Roser), has been detected in Belgium since 2010, after several decades without any reporting. It had indeed caused serious damages between 1965 and 1970. This insect is a European cereal pest whose larvae feed on stems and engender saddle-shaped depressions, resulting in yield losses. Face with the resurgence of this pest, it was decided to study its spatial distribution and, because serious damages were observed in some regions, to develop effective curative control. To date, chemical protection seems to be the only immediate solution in case of heavy emergences. Experimentation was conducted in a highly infested field (Meetkerke, Belgian Polders), according to a randomized complete blocks arrangement with four replications. Foremost, a lambdacyhalothrin-based insecticide was used to evaluate efficiency of several protection schemes, ranging between one and four spray(s). The large spread of flights observed during the 2011 spring allowed to highlight the effect of treatment date on the attack intensity and also on the galls distribution along the stem, on the different internodes: the lower internodes were protected by the early sprayings, while last sprayings induced reduction of galls number on the upper internodes. Moreover, several insecticides already registrated in cereals against aphids were compared for their efficacy against saddle gall midge. Studied pyrethroids have shown a very good efficacy, ranging between 75% and 87%, when applied twice with a 2 weeks interval. To be efficient, insecticide applications must thus be synchronized with the flights and egg-laying periods. Monitoring the phenology of flights is thus essential as part of integrated pest management against saddle gall midge. Source

Ivanov I.P.,University of Liege | Ivanov I.P.,RAS Sobolev Institute of Mathematics | Vdovin E.,RAS Sobolev Institute of Mathematics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

N-Higgs-doublet models (NHDM) are among the most popular examples of electroweak symmetry breaking mechanisms beyond the Standard Model. Discrete symmetries imposed on the NHDM scalar potential play a pivotal role in shaping the phenomenology of the model, and various symmetry groups have been studied so far. However, in spite of all efforts, the classification of finite Higgs-family symmetry groups realizable in NHDM for any N>2 is still missing. Here, we solve this problem for the three-Higgs-doublet model by making use of Burnside's theorem and other results from pure finite group theory which are rarely exploited in physics. Our method and results can also be used beyond high-energy physics, for example, in the study of possible symmetries in three-band superconductors. © 2012 American Physical Society. Source

Ivanov I.P.,University of Liege | Ivanov I.P.,RAS Sobolev Institute of Mathematics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We show that colliding vortex beams instead of (approximate) plane waves can lead to a direct measurement of how the overall phase of the plane wave scattering amplitude changes with the scattering angle. Since vortex beams are coherent superpositions of plane waves with different momenta, their scattering amplitude receives contributions from plane wave amplitudes with distinct kinematics. These contributions interfere, leading to the measurement of their phase difference. Although interference exists for any generic wave packet collision, we show that using vortex beams dramatically enhances sensitivity to the phase in comparison with nonvortex beams. Since the overall phase is inaccessible in a plane wave collision, this measurement would be of great importance for a number of topics in hadronic physics, for example, meson production in the resonance region, physics of nucleon resonances, and small angle elastic hadron scattering. © 2012 American Physical Society. Source

Extensive research activity is currently devoted to controlled drug delivery systems, mainly as nano-sized particles. Although biocompatible and (bio)degradable polymers play a key role in this field, their shaping into colloidal particles (e.g., polymeric micelles and nanoparticles) usually requires the proper design of amphiphilic copolymers as effective stabilizers. Strategies for synthesizing these copolymers that preserve the intrinsic properties of the constitutive polymers are discussed in this article. Synthesis of amphiphilic copolymers with a more complex structure and endowed with functionality is also considered, with the purpose of enhancing the performance of the nanocarriers. The focus is increasingly on nanocarriers of the third generation, which resist coalescence and elimination by the immune system, and which are readily incorporated into chosen target cells. The more recent quest is for smart nanocarriers that exhibit the additional capacity of being stimuli-responsive. Source

Anselme P.,University of Liege
Behavioural Processes | Year: 2015

There is a vast literature on the behavioural effects of partial reinforcement in Pavlovian conditioning. Compared with animals receiving continuous reinforcement, partially rewarded animals typically show (a) a slower development of the conditioned response (CR) early in training and (b) a higher asymptotic level of the CR later in training. This phenomenon is known as the partial reinforcement acquisition effect (PRAE). Learning models of Pavlovian conditioning fail to account for it. In accordance with the incentive salience hypothesis, it is here argued that incentive motivation (or 'wanting') plays a more direct role in controlling behaviour than does learning, and reward uncertainty is shown to have an excitatory effect on incentive motivation. The psychological origin of that effect is discussed and a computational model integrating this new interpretation is developed. Many features of CRs under partial reinforcement emerge from this model. © 2014 Elsevier B.V. Source

This paper presents the results of the analysis of the very first dedicated X-ray observation with XMM-Newton of WR 106. This carbon-rich WC9d Wolf-Rayet star belongs to the category of persistent dust makers (WCd stars). The issue of the multiplicity of these dust makers is pivotal to understand the dust formation process, and in this context X-ray observations may allow to reveal an X-ray emission attributable to colliding-winds in a binary system. The main result of this analysis is the lack of detection of X-rays coming from WR 106. Upper limits on the X-ray flux are estimated, but the derived numbers are not sufficient to provide compelling constraints on the existence or not of a colliding-wind region. Detailed inspection of archive data bases reveals that persistent dust makers have been poorly investigated by the most sensitive X-ray observatories. Certainly, the combination of several approaches to indirectly constrain their multiplicity should be applied to lift a part of the veil on the nature of these persistent dust makers. © 2015 Elsevier B.V.All right sreserved. Source

Sluse F.E.,University of Liege
Advances in Experimental Medicine and Biology | Year: 2012

Uncoupling proteins are a subfamily of the mitochondrial anion carrier family. They are widespread in the whole eukaryotic world with a few exceptions and present tissue specific isoforms in higher organisms. They mediate purine nucleotide-sensitive free fatty acid-activated proton inward flux through the inner mitochondrial membrane. This proton flux occurs at the expense of the proton motive force build up by the respiration and weakens the coupling between respiration and ATP synthesis. In this chapter we describe current and reliable knowledge of uncoupling proteins. A new methodology allowing study of their activity and regulation during phosphorylating respiration is described. It has entitled us to assert that all uncoupling proteins share common mechanisms of activation and regulation. This is of the utmost importance in order to understand the physiological roles of UCPs as well as their participation in pathological processes since every role of the UCPs in every cell is an integral part of their function and regulation. The central role of reduction level of ubiquinone in the control of their regulation is well-argued. Their potential and reliable roles in thermogenesis, reactive oxygen species prevention and energy flow are discussed as well as their role in some pathological disorders. © 2012 Springer Science+Business Media B.V. Source

This article presents the first hypotheses and questions developed from a clinical study on the representation of the parental function by lesbian couples asking for Artificial Insemination by Donor (AID). The early French speaking and English speaking reference to the debate on same sex parenthood within the psychoanalytical community led us to structure our qualitative data analysis (case analysis of thirty two couples) around two main issues. First, AID can be seen as an experience which introduces a third person to the lesbian couple and carries an important paradox for the psyche of all those involved ; secondly, it is useful to analyse the psychic developments linked to access to same sex parenthood, and in particular how subjects construe themselves as biological or social mothers. This two-pronged analysis based on clinical cases actually serves a metapsychological reflection on the concept of psychic bisexuality as a key element of psychic development for lesbian couples. © érès. Tous droits réservés pour tous pays. Source

Orbach R.,Hebrew University of Jerusalem | Remacle F.,University of Liege | Levine R.D.,Hebrew University of Jerusalem | Willner I.,Hebrew University of Jerusalem
Chemical Science | Year: 2014

Scaffolding proteins play a central role in many regulatory cellular networks, where signalling proteins trigger different, and even orthogonal biological pathways. Such biological regulatory networks can be duplicated by multiplexer/demultiplexer logic operations. We present the use of libraries of Mg2+-dependent DNAzyme subunits as computational moduli for the construction of 2:1 and 4:1 multiplexers and a 1:2 demultiplexer. In the presence of the appropriate inputs, and the presence or absence of selector units, the guided assembly of the DNAzyme subunits to form active Mg 2+-dependent DNAzyme proceeds. The formation of the active DNAzyme nanostructures is controlled by the energetics associated with the resulting duplexes between the inputs/selectors and the DNAzyme subunits. The library subunits are designed in such a way that, in the presence of the appropriate inputs/selectors, the inputs are knocked-down or triggered-on to yield the respective multiplexer/demultiplexer operations. Fluorescence is used as the readout for the outputs of the logic operations. The DNAzyme-based multiplexer/demultiplexer systems present biomolecular assemblies for data compression and decompression. This journal is © The Royal Society of Chemistry 2014. Source

Orbach R.,Hebrew University of Jerusalem | Wang F.,Hebrew University of Jerusalem | Lioubashevski O.,Hebrew University of Jerusalem | Levine R.D.,Hebrew University of Jerusalem | And 2 more authors.
Chemical Science | Year: 2014

In nature, post-transcriptional alternative splicing processes expand the proteome biodiversity, providing means to synthesize various protein isoforms. We describe the input-guided assembly of a DNAzyme-based full-adder computing system, which mimics functions of the natural processes by increasing the diversity of logic elements by the reconfiguration of the inputs. The full-adder comprises the simultaneous operation of three inputs that yield two different output signals, acting as sum and carry bits. The DNAzyme-based full-adder system consists of a library of Mg2+-dependent DNAzyme subunits and their substrates that are modified by two different fluorophore/quencher pairs that encode the sum and carry outputs. The input-guided assembly of DNAzyme subunits, formed by three inputs composed of nucleic acid hairpin structures, leads to computing modules that yield the sum and carry outputs of the full-adder. In the presence of a single input the DNAzyme computing module yields the sum fluorescence output. In the presence of two of the inputs, the reconfiguration of the input structures proceeds, leading to an input-guided computing module that yields the carry fluorescence output. By introducing all the three inputs the sequential inter-input hybridization leads to the reconfiguration of the inputs into polymer wires. These include binding sites for two types of DNAzyme and their substrates leading to the carry and sum fluorescence outputs. The advantages of the simultaneous three-input operation of the full-adder and the possibilities to implement DNAzyme-based computing modules for cascading full-adders are discussed. © 2014 the Partner Organisations. Source

Piette J.,University of Liege
Photochemical and Photobiological Sciences | Year: 2015

The response of tumors to photodynamic therapy (PDT) largely varies depending upon the intensity of the stress created in the cancer cells and also in the local environment. Singlet oxygen has been demonstrated, in many instances, to be the primary reactive oxygen species generated by PDT and responsible for most of the cellular effects. Cancer cells have developed various sensors which activate signalling pathways in response to PDT, and the nature of the activated pathway varies with the PDT stress intensity. At low doses of PDT, signalling pathways allow cancer cells to both proliferate and switch on pro-survival responses such as autophagy. Above a certain level of PDT stress intensity, cancer cells cannot cope with the heavy damage, and signalling pathways leading to cell death are activated. Two types of regulated cell death have been shown to be induced by PDT: apoptosis and necrosis. Signalling pathways activating NF-κB transcription factors have the peculiar characteristic of being activated both at low and high doses of PDT. These pathways coordinate the cross-talk between the immune system via the release of cytokines and chemokines and an anti-cell death response via the control of apoptosis and necrosis. Therefore, NF-κB induced by PDT appears to play a positive role in educating the immune system to fight tumors but also a negative role in helping cancer cells to survive the stress generated by singlet oxygen. This is why NF-κB cannot easily be considered as a pharmacological target whose inhibition will favor tumor cell eradication by PDT. © The Royal Society of Chemistry and Owner Societies 2015. Source

Grodent D.,University of Liege
Space Science Reviews | Year: 2015

The morphologies of the ultraviolet auroral emissions on the giant gas planets, Jupiter and Saturn, have conveniently been described with combinations of a restricted number of basic components. Although this simplified view is very handy for a gross depiction of the giant planets’ aurorae, it fails to scrutinize the diversity and the dynamics of the actual features that are regularly observed with the available ultraviolet imagers and spectrographs. In the present review, the typical morphologies of Jupiter and Saturn’s aurorae are represented with an updated and more accurate set of components. The use of sketches, rather than images, makes it possible to compile all these components in a single view and to put aside ultraviolet imaging technical issues that are blurring the emission sources, thus preventing one from disentangling the different auroral signatures. The ionospheric and magnetospheric processes to which these auroral features allude can then be more easily accounted. In addition, the use of components of the same kind for both planets may help to put forward similarities and differences between Jupiter and Saturn. The case of the ice giants Uranus and Neptune is much less compelling since their weak auroral emissions are very poorly documented and one can only speculate about their origin. This review presents a current perspective that will inevitably evolve in the future, especially with upcoming observing campaigns and forthcoming missions like Juno. © 2014, Springer Science+Business Media Dordrecht. Source

Wieland P.,Robert Bosch GmbH | Sepulchre R.,University of Liege | Allgower F.,University of Stuttgart
Automatica | Year: 2011

Output synchronization of a network of heterogeneous linear statespace models under time-varying and directed interconnection structures is investigated. It is shown that, assuming stabilizability and detectability of the individual systems and imposing very mild connectedness assumptions on the interconnection structure, an internal model requirement is necessary and sufficient for synchronizability of the network to polynomially bounded trajectories. The resulting dynamic feedback couplings can be interpreted as a generalization of existing methods for identical linear systems. © 2011 Elsevier Ltd. All rights reserved. Source

Bousquet E.,ETH Zurich | Bousquet E.,University of Liege | Spaldin N.,ETH Zurich
Physical Review Letters | Year: 2011

We use symmetry analysis to show that the G-, C-, and A-type antiferromagnetic Pnma perovskites can exhibit magnetoelectric (ME) responses when a ferroelectric instability is induced with epitaxial strain. Using first-principles calculations we compute the values of the allowed ME response in strained CaMnO3 as a model system. Our results show that large linear and non-linear-ME responses are present and can diverge when close to the ferroelectric phase transition. By decomposing the electronic and ionic contributions, we explore the detailed mechanism of the ME response. © 2011 American Physical Society. Source

Medicine combines the characteristics of both a science and an art. The main objective is to cure the patient (or at least to alleviate symptoms). The first step of the global medical approach is to make a diagnosis, which will determine the therapy. Since Hippocrates, semiology, i.e. the study of both symptoms and signs, is crucial to make or guide the disease diagnosis. The development of more and more sophisticated medical technologies may lead to believe that semiology is not useful anymore in medical practice. It is absolutely not true because a careful semiology can provide precise diagnoses in a majority of cases or, at least, can lead to a limited differential diagnosis that helps in the selection of a few well defined complementary investigations. The aim of this article targeting mainly medical students is to emphasize the key rules of a well done medical interviewing, which should progress from an "analytical" approach to a "syndromic" approach, combining knowledge, know-how and self-management skills. Source

Bousquet E.,University of California at Santa Barbara | Bousquet E.,University of Liege | Bousquet E.,ETH Zurich | Spaldin N.A.,ETH Zurich | Delaney K.T.,University of California at Santa Barbara
Physical Review Letters | Year: 2011

We show that the electronic part of the linear magnetoelectric response, usually omitted in first-principles studies, can be comparable in magnitude to that mediated by polar lattice distortions, even in strong magnetoelectrics. Using a self-consistent response to a Zeeman field for noncollinear spins, we show how polarization emerges in magnetoelectrics through both electronic and lattice contributions-analogous to the high- and low-frequency responses of dielectrics. The approach we use is computationally simple, and can be used to study linear and nonlinear responses to magnetic fields. © 2011 American Physical Society. Source

Matagne N.,University of Mons | Stancu F.,University of Liege
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

A simple procedure within the 1/Nc expansion method where all the Nc quarks are treated on the same footing has been found successful in describing mixed symmetric negative parity baryon states belonging to the [70,ℓ-] multiplets of the N=1 and 3 bands. Presently it is applied to mixed symmetric positive parity [70,0+] and [70,2 +] multiplets of the N=2 band. We search for the most dominant terms in the mass formula. The results are compared to those obtained in the procedure where the system is separated into a core and an excited quark. We find that both the spin and flavor operators of the entire system of Nc quarks play dominant roles in describing the data, like for negative parity states. As a by-product we present the contribution of the leading spin-flavor singlet term as a function of the band number, which hints at distinct Regge trajectories for the symmetric and mixed symmetric states. © 2013 American Physical Society. Source

Zorzi M.,University of Liege
Mathematics of Control, Signals, and Systems | Year: 2014

We approximate a given rational spectral density by one that is consistent with prescribed second-order statistics. Such an approximation is obtained by selecting the spectral density having minimum "distance" from under the constraint corresponding to imposing the given second-order statistics. We analyze the structure of the optimal solutions as the minimized "distance" varies in the Alpha divergence family. We show that the corresponding approximation problem leads to a family of rational solutions. Secondly, such a family contains the solution which generalizes the Kullback-Leibler solution proposed by Georgiou and Lindquist in 2003. Finally, numerical simulations suggest that this family contains solutions close to the non-rational solution given by the principle of minimum discrimination information. © 2013 Springer-Verlag London. Source

Parkin E.R.,University of Liege | Parkin E.R.,University of Leeds | Pittard J.M.,University of Leeds
Monthly Notices of the Royal Astronomical Society | Year: 2010

Hydrodynamical models of colliding hypersonic flows are presented which explore the dependence of the resulting dynamics and the characteristics of the derived X-ray emission on numerical conduction and viscosity. For the purpose of our investigation, we present models of colliding flow with plane-parallel and cylindrical divergence. Numerical conduction causes erroneous heating of gas across the contact discontinuity which has implications for the rate at which the gas cools. We find that the dynamics of the shocked gas and the resulting X-ray emission are strongly dependent on the contrast in the density and temperature either side of the contact discontinuity, these effects being strongest where the post-shock gas of one flow behaves quasi-adiabatically while the post-shock gas of the other flow is strongly radiative. Introducing additional numerical viscosity into the simulations has the effect of damping the growth of instabilities, which in some cases act to increase the volume of shocked gas and can re-heat gas via sub-shocks as it flows downstream. The resulting reduction in the surface area between adjacent flows, and therefore in the amount of numerical conduction, leads to a commensurate reduction in spurious X-ray emission, though the dynamics of the collision are compromised. The simulation resolution also affects the degree of numerical conduction. A finer resolution better resolves the interfaces of high density and temperature contrast, and although numerical conduction still exists the volume of affected gas is considerably reduced. However, since it is not always practical to increase the resolution, it is imperative that the degree of numerical conduction is understood so that inaccurate interpretations can be avoided. This work has implications for the dynamics and emission from astrophysical phenomena which involve high Mach number shocks. © 2010 The Authors. Journal compilation © 2010 RAS. Source

Bourguignon J.-P.,University of Liege | Juul A.,Copenhagen University
Endocrine Development | Year: 2012

Puberty is unique in the sense that its onset shows an extraordinary individual variability of about 5 years, the basis of which being still elusive despite research efforts to understand the reason why. Continuing changes in environmental influences and interaction with genetic determinants are suggested by the still evolving pattern of the pubertal process both clinically and mechanistically. For instance, secular trends towards earlier breast development have been observed during the two past decades in some countries, resulting in possible skewing of the age distribution of that pubertal sign with less obvious changes in menarcheal age. Conceptually, puberty and subsequent reproduction appear now to be influenced by conditions not only at the time when they occur, but also during fetal and perinatal life. In addition, these influences can be apparently opposing since early maturation follows fetal malnourishment and postnatal overfeeding. In this review, the semiology and pathophysiology of puberty are discussed in a lifelong developmental perspective. Copyright © 2012 S. Karger AG, Basel. Source

Chatzivasileiadis S.,ETH Zurich | Ernst D.,University of Liege | Andersson G.,ETH Zurich
Renewable Energy | Year: 2013

This paper puts forward the vision that a natural future stage of the electricity network could be a grid spanning the whole planet and connecting most of the large power plants in the world: this is the "Global Grid". The main driving force behind the Global Grid will be the harvesting of remote renewable sources, and its key infrastructure element will be the high capacity long transmission lines. Wind farms and solar power plants will supply load centers with green power over long distances. This paper focuses on the introduction of the concept, showing that a globally interconnected network can be technologically feasible and economically competitive. We further highlight the multiple opportunities emerging from a global electricity network such as smoothing the renewable energy supply and electricity demand, reducing the need for bulk storage, and reducing the volatility of the energy prices. We also discuss possible investment mechanisms and operating schemes. Among others, we envision in such a system a global power market and the establishment of two new coordinating bodies, the "Global Regulator" and the "Global System Operator". © 2013 Elsevier Ltd. Source

Zarate-Minano R.,University of Castilla - La Mancha | Van Cutsem T.,University of Liege | Milano F.,University of Castilla - La Mancha | Conejo A.J.,University of Castilla - La Mancha
IEEE Transactions on Power Systems | Year: 2010

This paper provides a methodology to restore transient stability. It relies on a well-behaved optimal power flow model with embedded transient stability constraints. The proposed methodology can be used for both dispatching and redispatching. In addition to power flow constraints and limits, the resulting optimal power flow model includes discrete time equations describing the time evolution of all machines in the system. Transient stability constraints are formulated by reducing the initial multi-machine model to a one-machine infinite-bus equivalent. This equivalent allows imposing angle bounds that ensure transient stability. The proposed optimal power flow model is tested and analyzed using an illustrative nine-bus system, the well-known New England 39-bus system, a ten-machine system, and a real-world 1228-bus system with 292 synchronous machines. © 2009 IEEE. Source

Dragutan I.,Romanian Academy of Sciences | Dragutan V.,Romanian Academy of Sciences | Demonceau A.,University of Liege
RSC Advances | Year: 2012

Examining advances in the class of natural and non-natural piperidine azasugars, important therapeutic agents and potent glycosidase inhibitors, this review looks at syntheses applying olefin metathesis as a highly efficient key step and gateway strategy for discovery of better iminosugar leads for treatment of widespread affections like viral and metabolic diseases. Amply illustrated is how ring-closing metathesis (RCM and RCEYM), promoted by commercial ruthenium alkylidene catalysts, manage to construct the common tetrahydropyridine core while cross-metathesis (CM), starting from this generic scaffold, provides general access to families of novel azasugars. Special consideration is given to high-profile iminosugar drugs of this class (1-deoxynojirimycin and congeners, adenophorine, fagomine, isofagomine and some of their N- and C-substituted analogues) stressing upon newest trends for enhancing biological activity and modulating previously unexploited targets in multispecific therapies. © 2012 The Royal Society of Chemistry. Source

Zorzi M.,University of Liege
IEEE Transactions on Automatic Control | Year: 2014

In this paper, we extend the Beta divergence family to multivariate power spectral densities. Similarly to the scalar case, we show that it smoothly connects the multivariate Kullback-Leibler divergence with the multivariate Itakura-Saito distance. We successively study a spectrum approximation problem, based on the Beta divergence family, which is related to a multivariate extension of the THREE spectral estimation technique. It is then possible to characterize a family of solutions to the problem. An upper bound on the complexity of these solutions will also be provided. Finally, we will show that the most suitable solution of this family depends on the specific features required from the estimation problem. © 1963-2012 IEEE. Source

Payez A.,University of Liege
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

In a series of papers, it has been shown that the distribution of polarization position angles for visible light from quasars is not random in extremely large regions of the sky. As explained in a recent article, the measurement of vanishing circular polarization for such quasars is an important problem for a mechanism involving the mixing with axionlike particles in external magnetic fields. In this paper, we stress that a recent report of similar coherent orientations of polarization in radio waves further disfavors the need for such particles, as an effect at these wavelengths would be extremely suppressed or would directly contradict data. © 2012 American Physical Society. Source

Lebon G.,University of Liege
Journal of Non-Equilibrium Thermodynamics | Year: 2014

This review paper is dedicated to a description of heat transport at micro and nanoscales from the viewpoint of Extended Irreversible Thermodynamics. After a short survey of the classical heat conduction laws, like those of Fourier, Cattaneo, and Guyer-Krumhansl, we briefly overview the hypotheses and objectives of Extended Irreversible Thermodynamics, which is particularly well suited to cope with processes at short length and time scales. A selection of some important items typical of nanomaterials and technology are reviewed. Particular attention is brought to the notion of effective thermal conductivity: its expression in terms of size and frequency dependence is formulated, its significant increase in nanofluids formed by a matrix and nanoparticles is discussed, the problem of pore-size dependence and its incidence on thermal rectifiers is also investigated. Transient heat conduction through thin one-dimensional films receives special treatment. The results obtained from a generalized Fourier law are compared with those provided by a more sophisticated ballistic-diffusion model. Our survey ends with general considerations on boundary conditions whose role is of fundamental importance in nanomaterials. © 2014 by Walter de Gruyter Berlin/Boston 2014. Source

The study of a production chain of raw milk cheeses (St Marcellin, Vercors area, France) led to the isolation of two Bifidobacterium populations: B. crudilactis and B. mongoliense, that were able to grow along the production chain. The aims of this study were to further detect and characterize these bacteria along the process and evaluate the ability of some strains to survive or grow in adverse conditions. Using PCR coupled with restriction fragment length polymorphism, B. crudilactis and B. mongoliense were detected in respectively 77% and 30% of St Marcellin cheeses from production chain after 21 days of ripening. They were present in more than half of all analyzed retail cheeses with counts going from 1.6 to 5 log cfu g-1 for B. crudilactis and 1.4 to 7 log cfu g-1 for B. mongoliense. Bifidobacterium mongoliense was sensitive to pH 2, with an observed decrease of at least 3 log for both studied strains (FR49/f/2 and FR41/2) after 1 h incubation. At pH 3, no significant decrease was observed. Good survival was observed for the same strains in presence of pancreatic juice with a decrease of less than one log. Survival of strain FR49/f/2 was better than FR41/2 with a decrease of 3 logarithms (in presence of 1% bile salts) and almost 2 logarithms (in presence of 0.5% bile salts). The genotypic analyses using total DNA-DNA hybridization, GC% content, 16S rRNA gene sequencing and multilocus sequencing analysis (MLSA) confirmed the classification of Bifidobacterium. crudilactis and B. mongoliense into two different clusters well separated from other bifidobacteria clusters. According to the observed characteristics such as survival in adverse conditions and their ability to grow under 12 °C during the manufacturing process of the cheeses, which has never been described for bifidobacteria and which is a very interesting technological asset, these B. crudilactis and B. mongoliense strains should be further investigated for a potential use in new food or in food supplements. Source

Lefebvre P.J.,University of Liege
Diabetes, Obesity and Metabolism | Year: 2011

As an introduction to the Symposium, we have reviewed the early steps in glucagon research from its discovery in 1923 to the establishment of the basics of the physiology and pathophysiology of the hormone after the description of a sensitive and specific radioimmunoassay by Unger and his co-workers in 1959. © 2011 Blackwell Publishing Ltd. Source

Mulder H.A.,Animal Breeding and Genomics Center | Calus M.P.L.,Animal Breeding and Genomics Center | Druet T.,University of Liege | Schrooten C.,Crv Inc.
Journal of Dairy Science | Year: 2012

Genomic selection using 50,000 single nucleotide polymorphism (50k SNP) chips has been implemented in many dairy cattle breeding programs. Cheap, low-density chips make genotyping of a larger number of animals cost effective. A commonly proposed strategy is to impute low-density genotypes up to 50,000 genotypes before predicting direct genomic values (DGV). The objectives of this study were to investigate the accuracy of imputation for animals genotyped with a low-density chip and to investigate the effect of imputation on reliability of DGV. Low-density chips contained 384, 3,000, or 6,000 SNP. The SNP were selected based either on the highest minor allele frequency in a bin or the middle SNP in a bin, and DAGPHASE, CHROMIBD, and multivariate BLUP were used for imputation. Genotypes of 9,378 animals were used, from which approximately 2,350 animals had deregressed proofs. Bayesian stochastic search variable selection was used for estimating SNP effects of the 50k chip. Imputation accuracies and imputation error rates were poor for low-density chips with 384 SNP. Imputation accuracies were higher with 3,000 and 6,000 SNP. Performance of DAGPHASE and CHROMIBD was very similar and much better than that of multivariate BLUP for both imputation accuracy and reliability of DGV. With 3,000 SNP and using CHROMIBD or DAGPHASE for imputation, 84 to 90% of the increase in DGV reliability using the 50k chip, compared with a pedigree index, was obtained. With multivariate BLUP, the increase in reliability was only 40%. With 384 SNP, the reliability of DGV was lower than for a pedigree index, whereas with 6,000 SNP, about 93% of the increase in reliability of DGV based on the 50k chip was obtained when using DAGPHASE for imputation. Using genotype probabilities to predict gene content increased imputation accuracy and the reliability of DGV and is therefore recommended for applications of imputation for genomic prediction. A deterministic equation was derived to predict accuracy of DGV based on imputation accuracy, which fitted closely with the observed relationship. The deterministic equation can be used to evaluate the effect of differences in imputation accuracy on accuracy and reliability of DGV. © 2012 American Dairy Science Association. Source

Namur O.,University of Liege | Namur O.,University of Cambridge | Charlier B.,Massachusetts Institute of Technology
Contributions to Mineralogy and Petrology | Year: 2012

Adcumulate formation in mafic layered intrusions is attributed either to gravity-driven compaction, which expels the intercumulus melt out of the crystal matrix, or to compositional convection, which maintains the intercumulus liquid at a constant composition through liquid exchange with the main magma body. These processes are length-scale and time-scale dependent, and application of experimentally derived theoretical formulations to magma chambers is not straightforward. New data from the Sept Iles layered intrusion are presented and constrain the relative efficiency of these processes during solidification of the mafic crystal mush. Troctolites with meso- to ortho-cumulate texture are stratigraphically followed by Fe-Ti oxide-bearing gabbros with adcumulate texture. Calculations of intercumulus liquid fractions based on whole-rock P, Zr, V and Cr contents and detailed plagioclase compositional profiles show that both compaction and compositional convection operate, but their efficiency changes with liquid differentiation. Before saturation of Fe-Ti oxides in the intercumulus liquid, convection is not active due to the stable liquid density distribution within the crystal mush. At this stage, compaction and minor intercumulus liquid crystallization reduce the porosity to 30%. The velocity of liquid expulsion is then too slow compared with the rate of crystal accumulation. Compositional convection starts at Fe-Ti oxide-saturation in the pore melt due to its decreasing density. This process occurs together with crystallization of the intercumulus melt until the residual porosity is less than 10%. Compositional convection is evidenced by external plagioclase rims buffered at An 61 owing to continuous exchange between the intercumulus melt and the main liquid body. The change from a channel flow regime that dominates in troctolites to a porous flow regime in gabbros results from the increasing efficiency of compaction with differentiation due to higher density contrast between the cumulus crystal matrix and the equilibrium melts and to the bottom-up decreasing rate of crystal accumulation in the magma chamber. © 2012 Springer-Verlag. Source

Feller G.,University of Liege
Journal of Physics Condensed Matter | Year: 2010

Psychrophilic microorganisms thrive in permanently cold environments, even at subzero temperatures. To maintain metabolic rates compatible with sustained life, they have improved the dynamics of their protein structures, thereby enabling appropriate molecular motions required for biological activity at low temperatures. As a consequence of this structural flexibility, psychrophilic proteins are unstable and heat-labile. In the upper range of biological temperatures, thermophiles and hyperthermophiles grow at temperatures > 100 °C and synthesize ultra-stable proteins. However, thermophilic enzymes are nearly inactive at room temperature as a result of their compactness and rigidity. At the molecular level, both types of extremophilic proteins have adapted the same structural factors, but in opposite directions, to address either activity at low temperatures or stability in hot environments. A model based on folding funnels is proposed accounting for the stability-activity relationships in extremophilic proteins. © 2010 IOP Publishing Ltd. Source

Margesin R.,University of Innsbruck | Feller G.,University of Liege
Environmental Technology | Year: 2010

Low temperature environments are numerous on Earth and have been successfully colonized by cold-loving organisms termed psychrophiles. Cold-adapted microorganisms can be used as cell factories for the production of unstable compounds as well as for bioremediation of polluted cold soils and wastewaters. Furthermore, their biomolecules, mainly proteins and enzymes characterized by a high catalytic activity and pronounced heat-lability, have already found useful applications in various domains such as molecular biology, medical research, industrial food or feed technologies, detergents or cosmetics. © 2010 Taylor & Francis. Source

Elbaz J.,Hebrew University of Jerusalem | Wang F.,Hebrew University of Jerusalem | Remacle F.,University of Liege | Willner I.,Hebrew University of Jerusalem
Nano Letters | Year: 2012

Nature performs complex information processing circuits, such the programmed transformations of versatile stem cells into targeted functional cells. Man-made molecular circuits are, however, unable to mimic such sophisticated biomachineries. To reach these goals, it is essential to construct programmable modular components that can be triggered by environmental stimuli to perform different logic circuits. We report on the unprecedented design of artificial pH-programmable DNA logic arrays, constructed by modular libraries of Mg2+- and UO2 2+-dependent DNAzyme subunits and their substrates. By the appropriate modular design of the DNA computation units, pH-programmable logic arrays of various complexities are realized, and the arrays can be erased, reused, and/or reprogrammed. Such systems may be implemented in the near future for nanomedical applications by pH-controlled regulation of cellular functions or may be used to control biotransformations stimulated by bacteria. © 2012 American Chemical Society. Source

Khan S.,Copenhagen University | Schoenen J.,University of Liege | Ashina M.,Copenhagen University
Cephalalgia | Year: 2014

Objective: The objective of this article is to review the prospect of treating migraine with sphenopalatine ganglion (SPG) neurostimulation. Background: Fuelled by preliminary studies showing a beneficial effect in cluster headache patients, the potential of treating migraine with neurostimulation has gained increasing interest within recent years, as current treatment strategies often fail to provide adequate relief from this debilitating headache. Common migraine symptoms include lacrimation, nasal congestion, and conjunctival injection, all parasympathetic manifestations. In addition, studies have suggested that parasympathetic activity may also contribute to the pain of migraineurs. The SPG is the largest extracranial parasympathetic ganglion of the head, innervating the meninges, lacrimal gland, nasal mucosa, and conjunctiva, all structures involved in migraine with cephalic autonomic symptoms. Conclusion: We propose two possible mechanisms of action: 1) interrupting the post-ganglionic parasympathetic outflow to inhibit the pain and cephalic autonomic symptoms, and 2) modulating the sensory processing in the trigeminal nucleus caudalis. To further explore SPG stimulation in migraineurs as regards therapeutic potential and mode of action, randomized clinical trials are warranted. © 2013 International Headache Society. Source

Kreusch M.,University of Liege
Letters in Mathematical Physics | Year: 2013

An explicit construction of central extensions of Lie superalgebras of Krichever-Novikov type is given. In the case of Jordan superalgebras related to the superalgebras of Krichever-Novikov type we calculate a 1-cocycle with coefficients in the dual space. © 2013 Springer Science+Business Media Dordrecht. Source

Barrandeguy M.,Instituto Nacional de Tecnologia Agropecuaria | Thiry E.,University of Liege
Veterinary Journal | Year: 2012

Equine coital exanthema (ECE) caused by equid herpesvirus 3 (EHV-3) is a contagious venereal disease characterised by the formation of painful papules, vesicles, pustules and ulcers on the external genitalia of both mares and stallions. EHV-3 is an alphaherpesvirus that is distinct from the other equine herpesviruses and endemic in most horse breeding populations worldwide. The negative impacts of ECE on equine breeding enterprises are the forced, temporary disruption of mating activities of mares and stallions, the additional care and supportive treatment that is required for affected horses, and the risk of virus spread by either fresh or frozen semen as well as by artificial insemination and embryo transfer. Because there are no effective surveillance systems to report ECE, its true prevalence and economic impact are difficult to assess and are probably underestimated. The purpose of this review is to describe the recent advances in understanding of EHV-3 infections and to consider the economic consequences of ECE within the current context of the equine industry. © 2011 Elsevier Ltd. Source

Magis D.,University of Liege | Raiche G.,University of Quebec at Montreal
Journal of Statistical Software | Year: 2012

This paper outlines a computerized adaptive testing (CAT) framework and presents an R package for the simulation of response patterns under CAT procedures. This package, called catR, requires a bank of items, previously calibrated according to the four-parameter logistic (4PL) model or any simpler logistic model. The package proposes several methods to select the early test items, several methods for next item selection, different estimators of ability (maximum likelihood, Bayes modal, expected a posteriori, weighted likelihood), and three stopping rules (based on the test length, the precision of ability estimates or the classification of the examinee). After a short description of the different steps of a CAT process, the commands and options of the catR package are presented and practically illustrated. Source

Microorganisms are able to attach to, grow on, and ultimately form biofilms on a large variety of surfaces, such as industrial equipment, food contact surfaces, medical implants, prostheses and operating rooms. Once organized into biofilms, bacteria are difficult to remove and kill, which increases the risk of cross-contamination and infection. One way to address the problem may thus be to develop antibacterial, anti-adhesion, 'easy cleaning' surfaces. In this study, stainless steel (SS) surfaces with antibacterial properties were created by embedding several antimicrobial peptides in a multilayer film architecture. The biocidal effect of these surfaces was demonstrated against both Gram-positive and Gram-negative bacteria according to two ISO tests. Also, coating SS surfaces with either mucin or heparin led to a reduction of S. epidermidis adhesion of almost 95% vs the bare substratum. Finally, by combining both antibacterial and anti-adhesion biomolecules in the same multilayer film, SS surfaces with better cleanability were produced. This surface coating property may help to delay the buildup of a dead bacterial layer which is known to progressively reduce exposure of the coating, leading to an undesirable decrease in the antibacterial effect of the surface. Source

Ceccopieri F.A.,University of Liege
The European Physical Journal C | Year: 2014

We consider forward neutron production in DIS within fracture functions formalism. By performing a QCD analysis of available data we extract proton-to-neutron fracture functions exploiting a method which is in close relation with the factorisation theorem for this class of processes. © 2014 The Author(s). Source

Porod W.,University of Wurzburg | Staub F.,University of Bonn | Vicente A.,University of Liege
The European Physical Journal C | Year: 2014

We present a new kit for the study of flavor observables in models beyond the standard model. The setup is based on the public codes SARAH and SPheno and allows for an easy implementation of new observables. The Wilson coefficients of the corresponding operators in the effective lagrangian are computed by SPheno modules written by SARAH. New operators can also be added by the user in a modular way. For this purpose a handy Mathematica package called the PreSARAH has been developed. This uses FeynArts and FormCalc to derive generic form factors at tree- and 1-loop levels and to generate the necessary input files for SARAH. This framework has been used to implement BR((Formula presented.)), BR((Formula presented.)), CR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)), (Formula presented.), (Formula presented.), (Formula presented.), BR((Formula presented.)), BR((Formula presented.)), BR((Formula presented.)) and BR((Formula presented.)) in SARAH. Predictions for these observables can now be obtained in a wide range of SUSY and non-SUSY models. Finally, the user can use the same approach to easily compute additional observables. © 2014 The Author(s). Source

The clinician has to cope with new advances in medicine. Traditional medicine, which is based upon pathophysiological reasoning and clinical experience, has been reinforced by evidence-based medicine, which relies on levels of evidence provided by controlled clinical trials carried out on cohorts of patients. Since a few years, personalized medicine has been put at the forefront. A therapy tailored to every patient, if possible characterized by biomarkers, among which, since the achievement of the whole human genome sequencing, an increasing number of genetic markers. Personalized medicine should be used as a complement of traditional and evidence-based medicine. Physicians should progressively integrate this new strategy in their therapeutic approach. Hence, clinicians have to face new challenges as far as scientific knowledge, practical applications and physician-patient relationship are concerned. Source

The cost of pharmacotherapy is increasing in the health care budget. The pharmaceutical industry is facing the exhaustion of medications that are largely prescribed and have a high profitability (blockbusters). Because of patient heterogeneity, there is a great interindividual variability of the responses to drug therapy. Thus, it is essential to better detect potential "good responders" to avoid waste of resources resulting from the prescription of expensive drugs to poor responders. The development of personalized medicine, or precision medicine, certainly offers opportunities to the pharmaceutical industry, but also exposes it to new big challenges. Source

The increasing interest for personalized medicine evolves together with two major technological advances. First, the new-generation, rapid and less expensive, DNA sequencing method, combined with remarkable progresses in molecular biology leading to the post-genomic era (transcriptomics, proteomics, metabolomics). Second, the refinement of computing tools (IT), which allows the immediate analysis of a huge amount of data (especially, those resulting from the omics approaches) and, thus, creates a new universe for medical research, that of "big data" analyzed by computerized modelling. This article for scientific communication and popularization briefly describes the main advances in these two fields of interest. These technological progresses are combined with those occurring in communication, which makes possible the development of artificial intelligence. These major advances will most probably represent the grounds of the future personalized medicine. Source

Type 2 diabetes represents a major medical and public health problem due to its huge heterogeneity, the alarming rise of its incidence worldwide and its associated vascular complications, which impair quality of life and reduce life expectancy. At the present time, a patient-centered approach is recommended for the management of type 2 diabetes patients. However, these recommendations are not easy to implement because we only have little objective evidences to establish individualized strategies. Following the recent introduction of new drug classes, a large number of combinations is offered to clinicians, but we do not have high quality interventional studies comparing these different therapeutic possibilities. Moreover, the response to pharmacological treatment can vary greatly from one subject to the other. Pharmacogenetics might be a useful tool to better characterize the patient. However, despite some progress, the evidence we now have is very preliminary and should not allow to improve significantly the individual management of type 2 diabetes in the near future. Source

Spallation reactions, as well as the standard theoretical tool for their study, namely the intra-nuclear cascade (INC) + evaporation model, are briefly introduced. The theoretical foundations and the domain of validity of the INC model are discussed in some detail. © 2011 Springer-Verlag. Source

Caves are privileged observatories of underground air and its carbon dioxide content. The carbon dioxide partial pressure in Belgian caves displays seasonal fluctuations with strong summer maxima. Besides, CO2 concentration has risen very significantly in Belgian caves since our first measurements in the nineteen sixties. To understand the cause of this rise, we have been measuring the air in the soil above the Comblain-au-Pont cave since 2008, with a device developed by Jean Godissart. These measurements show clear seasonal variations, the maximum occurring in early summer, well before the maximum in the caves. This confirms the influence of vegetation as a source of carbon dioxide in the caves. It is well known that atmospheric CO2 concentration and temperature are two factors influencing the growth of vegetation. And the stock of vegetation is indeed increasing in Belgium, where the volume of wood in tree trunks in the Walloon Region forests rose about 30% in the thirty years from 1984 to 2005. The increase in vegetation is of course correlative with the soil biological activity. We firmly believe that this explains a large part of the CO2 rise in cave air. Source

Hypertension has a high world-wide prevalence, affecting more than 25 % of the population; it remains the silent killer number one in cardiovascular pathology. Although lowering high blood pressure is protective, perfect control of hypertension is far from being optimal in spite of many international guidelines regularly updated according to published scientific studies. A personalized approach of hypertension management is an attractive way to improve this situation. Tools are developing (pharmacogenetics, pharmacometabolomics), but their use in daily clinical practice seems premature. At the present time, it is the physician experience which offers the best opportunity to propose the best treatment to the best patient. The management of hypertension remains a difficult task in some cases. Patient education is also crucial to improve drug compliance. Source

Scheen A.J.,University of Liege
Expert Opinion on Drug Safety | Year: 2013

Introduction: Metformin is the first-choice drug in the management of type 2 diabetes. However, most patients require a combined therapy to reach and/or maintain targets of glucose control. Dipeptidyl peptidase-4 (DPP-4) inhibitors offer new options for combined therapy with metformin. Linagliptin shares a similar pharmacodynamic (PD) profile with other gliptins, but has a unique pharmacokinetic (PK) profile characterized by negligible renal excretion. Areas covered: An extensive literature search was performed to analyze the potential PK/PD interactions between linagliptin and metformin. They are not prone to PK drug-drug interactions. The two compounds may be administered together, either separately or using a fixed-dose combination (FDC) as shown by bioequivalence studies. The addition of linagliptin in patients not well controlled with metformin alone has proven its efficacy in improving glucose levels with a good safety profile. Initial co-administration of linagliptin plus metformin improves glucose control more potently than either compound separately, without hypoglycemia, weight gain or increased metformin-related gastrointestinal side effects. Expert opinion: The linagliptin plus metformin combination may offer some advantages over the classical sulfonylurea-metformin combination. Even if linagliptin is safe in patients with renal impairment, the use of metformin (and thus of the linagliptin plus metformin FDC) is still controversial in this population. © 2013 Informa UK, Ltd. Source

Denoel M.,University of Liege
Biodiversity and Conservation | Year: 2012

The recent increase in the number of monitoring schemes has formed the basis for high quality distribution atlases. This provides the opportunity of estimating global and specific decline patterns across regional and national borders. In this framework, this study focused on four sympatric newt species-including the great crested newt (Triturus cristatus), an Annex 2 European Habitats Directive species, over six geographic areas (five countries) in Western Europe. A relative comparison of distribution maps across time is used here and is based on more than twelve thousands occupied grid cells. It benefits from the definition of a guild, as these species are simultaneously detectable in wetlands. T. cristatus and the alpine newt (Mesotriton alpestris) were the most and the least threatened newt species, respectively, whereas the palmate (Lissotriton helveticus) and smooth newt (Lissotriton vulgaris) had an intermediate decline level at both coarse and fine grain resolutions. However, regional variations across Europe and scale effects were also found. On one hand, these results show that T. cristatus is not only regionally threatened but suffers from a global decline in Western Europe. On another hand, the results indicate that patterns of decline are not uniform within Europe and that species often considered as common and not threatened are, in fact, declining more than others. Finally, the proposed methodology, i. e. using guilds to assess relative decline, would be useful as a complement to other standardized methods in correctly advising conservation managers and policy makers, particularly for species with more subtle declines. © 2012 Springer Science+Business Media B.V. Source

Pasleau F.,University of Liege
Revue Medicale de Liege | Year: 2015

The fundamentals of Evidence-Based Medicine (EBM) are the clinical experience, the application of best evidences from research and the consideration of patient expectations. It enabled significant progresses in the management of diseases with a low or multifactorial causality. But it has also led to unintended negative consequences, partly related to conflicts of interest. The objective of this article is to bring the attention back to the scientific rigor that must sustain the medical practice, namely in the occurrence : 1) formulating a question that addresses all the elements of an individual clinical situation; 2) exploring the literature systematically; 3) estimating the degree of confidence in the conclusions of clinical trials. EBM provides intuitive tools to address some uncomfortable concepts of biostatistics and to identify the biases and the embellished data that invalidate many studies. However, it is difficult to decide of the care of a single patient from observations issued from the comparison of heterogeneous groups. Personalized medicine should help to overcome this difficulty and should facilitate clinical decision making by targeting the patients who are most likely to benefit from an intervention without much inconvenience. Source

Agrawal S.,University of Texas at Austin | Boneh D.,Stanford University | Boyen X.,University of Liege
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

We construct an efficient identity based encryption system based on the standard learning with errors (LWE) problem. Our security proof holds in the standard model. The key step in the construction is a family of lattices for which there are two distinct trapdoors for finding short vectors. One trapdoor enables the real system to generate short vectors in all lattices in the family. The other trapdoor enables the simulator to generate short vectors for all lattices in the family except for one. We extend this basic technique to an adaptively-secure IBE and a Hierarchical IBE. © 2010 Springer-Verlag. Source

More patients are actually treated due to the incredible improvements of medical care, especially in the field of pharmacotherapy. Medical guidelines are based on the results of controlled trials. This kind of medicine, also called Evidence Based Medicine (EBM), is actually the cornerstone of good clinical practice. Nevertheless, it remains a lot of patients disappointed by the fact that they have no medical gain of their treatment. The reason is that each patient has his/her own metabolic characteristics. Better is the characterization of such patients, better will be the treatment targeting them. It is what is called the personalized medicine. To reach this challenge, pharmacogenetic advances would be helpful. From an antagonism between EBM and personalized medicine, this new medical paradigm has to consider these approaches as partners. To reach this goal, medical doctors, legal authorities and pharmaceutical companies have to be responsible in front of these new ethical challenges. Source

Morel T.,University of Liege | Miglio A.,University of Birmingham
Monthly Notices of the Royal Astronomical Society: Letters | Year: 2012

The frequency of maximum oscillation power measured in dwarfs and giants exhibiting solar-like pulsations provides a precise, and potentially accurate, inference of the stellar surface gravity. An extensive comparison for about 40 well-studied pulsating stars with gravities derived using classical methods (ionization balance, pressure-sensitive spectral features or location with respect to evolutionary tracks) supports the validity of this technique and reveals an overall remarkable agreement with mean differences not exceeding 0.05dex (although with a dispersion of up to ∼0.2dex). It is argued that interpolation in theoretical isochrones may be the most precise way of estimating the gravity by traditional means in nearby dwarfs. Attention is drawn to the usefulness of seismic targets as benchmarks in the context of large-scale surveys. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS. Source

Matagne N.,University of Mons | Stancu F.,University of Liege
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We discuss the compatibility between the quark-shell picture and the meson-nucleon scattering picture in large N c QCD for mixed symmetric =1 states previously analyzed by using a simple Hamiltonian including operators up to order O(Nc0) defined in the standard ground state symmetric core+excited quark procedure. Here we introduce a Hamiltonian of order O(Nc0) defined in a new approach where the separation of the system into two parts is not required. Three degenerate sets of states (towers) with the same quantum numbers as in the scattering picture and in the standard procedure are obtained. Thus the compatibility is equally achieved. The eigenvalues of the presently chosen Hamiltonian also have simple analytic expressions, depending linearly on the three dynamical coefficients entering the Hamiltonian. This reinforces the validity of the new approach which had already successfully described excited negative parity baryons in a large energy range. © 2012 American Physical Society. Source

Some patients are exposed to complex clinical situations, which impose a careful analysis of both the indications and contra-indications of ongoing pharmacological treatments as well as of the dosing or drug adjustments to be proposed. This article illustrates some problems encountered when a new drug therapy is initiated, when medications with narrow therapeutic window should be supervised and when some drugs should be stopped mainly for safety reasons. The clinical case relates the story of a patient with type 2 diabetes, arterial hypertension and coronary heart disease, who presents a congestive heart failure associated with an episode of atrial fibrillation and a severe renal insufficiency. Source

Waltregny D.,University of Liege
Surgical technology international | Year: 2012

Tension-free suburethral tapes have revolutionized the surgical treatment of female stress urinary incontinence (SUI). These tapes are inserted by way of a retropubic or transobturator route. The inside-out tension-free vaginal tape transobturator approach, or TVT-Obturator system (TVT-O, Ethicon Women's Health and Urology, Somerville, NJ), was developed ten years ago with the aim of minimizing the risk of urinary tract injuries associated with retropubic and outside-in transobturator tapes while reproducibly ensuring minimal tissue dissection. Cadaveric studies have shown that the anatomical trajectory of the TVT-O tape is strictly perineal and courses away from neighboring obturator and pudendal neurovascular structures. Several meta-analyses have shown similar SUI cure rates after retropubic and transobturator tape procedures. Yet, the transobturator route may be associated with less voiding dysfunction, blood loss, bladder perforation, and shorter operating time. The original TVT-O procedure was modified with the aim of reducing the incidence of postoperative groin pain as well as the rather theoretical risk of obturator nerve injury. This modified procedure, named TVT-ABBREVO (Ethicon Women's Health and Urology, Somerville, NJ), utilizes a shortened, 12-cm-long polypropylene tape. In addition, perforation of the obturator membrane with the scissors and guide is avoided in order to reduce the depth of lateral dissection, and consequently, to maximize securing of the tape within the obturator muscular/aponeurotic structures. In a comparative anatomical study, it was indeed observed that the shorter tape traversed less muscular structures (with no or only a minimal amount of tape lying in the adductor muscles) than its original counterpart, while still consistently anchoring in the obturator membrane at a similarly safe distance from the obturator canal. In a single-center randomized clinical trial, after a 3-year minimum follow-up, the modified TVT-O procedure with a shorter tape and reduced dissection was found to be as safe and efficient as the primal procedure for treating female SUI, with less severe and frequent groin pain in the immediate postoperative period. Source

du Jardin P.,University of Liege
Scientia Horticulturae | Year: 2015

A plant biostimulant is any substance or microorganism applied to plants with the aim to enhance nutrition efficiency, abiotic stress tolerance and/or crop quality traits, regardless of its nutrients content. By extension, plant biostimulants also designate commercial products containing mixtures of such substances and/or microorganisms. The definition proposed by this article is supported by arguments related to the scientific knowledge about the nature, modes of action and types of effects of biostimulants on crop and horticultural plants. Furthermore, the proposed definition aims at contributing to the acceptance of biostimulants by future regulations, especially in the EU, drawing the lines between biostimulants and fertilisers, pesticides or biocontrol agents. Many biostimulants improve nutrition and they do so regardless of their nutrients contents. Biofertilisers, which we propose as a subcategory of biostimulants, increase nutrient use efficiency and open new routes of nutrients acquisition by plants. In this sense, microbial biostimulants include mycorrhizal and non-mycorrhizal fungi, bacterial endosymbionts (like Rhizobium) and Plant Growth-Promoting Rhizobacteria. Thus, microorganisms applied to plants can have a dual function of biocontrol agent and of biostimulant, and the claimed agricultural effect will be instrumental in their regulatory categorization. The present review gives an overview of the definition and concept of plant biostimulants, as well as the main categories. This paper will also briefly describe the legal and regulatory status of biostimulants, with a focus on the EU and the US, and outlines the drivers, opportunities and challenges of their market development. © 2015 The Author. Source

Galan M.,Montpellier SupAgro | Pages M.,Montpellier SupAgro | Pages M.,University of Liege | Cosson J.-F.,Montpellier SupAgro
PLoS ONE | Year: 2012

Rodentia is the most diverse order among mammals, with more than 2,000 species currently described. Most of the time, species assignation is so difficult based on morphological data solely that identifying rodents at the specific level corresponds to a real challenge. In this study, we compared the applicability of 100 bp mini-barcodes from cytochrome b and cytochrome c oxidase 1 genes to enable rodent species identification. Based on GenBank sequence datasets of 115 rodent species, a 136 bp fragment of cytochrome b was selected as the most discriminatory mini-barcode, and rodent universal primers surrounding this fragment were designed. The efficacy of this new molecular tool was assessed on 946 samples including rodent tissues, feces, museum samples and feces/pellets from predators known to ingest rodents. Utilizing next-generation sequencing technologies able to sequence mixes of DNA, 1,140 amplicons were tagged, multiplexed and sequenced together in one single 454 GS-FLX run. Our method was initially validated on a reference sample set including 265 clearly identified rodent tissues, corresponding to 103 different species. Following validation, 85.6% of 555 rodent samples from Europe, Asia and Africa whose species identity was unknown were able to be identified using the BLASTN program and GenBank reference sequences. In addition, our method proved effective even on degraded rodent DNA samples: 91.8% and 75.9% of samples from feces and museum specimens respectively were correctly identified. Finally, we succeeded in determining the diet of 66.7% of the investigated carnivores from their feces and 81.8% of owls from their pellets. Non-rodent species were also identified, suggesting that our method is sensitive enough to investigate complete predator diets. This study demonstrates how this molecular identification method combined with high-throughput sequencing can open new realms of possibilities in achieving fast, accurate and inexpensive species identification. © 2012 Galan et al. Source

Toma T.,Durham University | Vicente A.,University of Liege
Journal of High Energy Physics | Year: 2014

We investigate lepton flavor violation in the scotogenic model proposed by Ma in which neutrinos acquire non-zero masses at the 1-loop level. Although some works exist in this direction, they have mainly focused on the radiative decay ℓ α → ℓ β γ. Motivated by the promising new projects involving other low-energy processes, we derive complete analytical expressions for ℓ α → 3 ℓ β and μ - e conversion in nuclei, and numerically study their impact on the phenomenology. We will show that these processes can actually have rates larger than the one for ℓ α → ℓ β γ, thus providing more stringent constraints and better experimental perspectives. © 2014 The Author(s). Source

Pissart A.,University of Liege
Zeitschrift fur Geomorphologie | Year: 2010

The ramparted depressions that exist on the Hautes Fagnes Plateau in Belgium, first interpreted in 1956 as the remnants of pingos are best explained as remnants of lithalsas (i.e., mineral palsas), formed from ice segregation within frozen ground (permafrost) of Younger Dryas age. These features have only been described previously from Belgium, Wales and Ireland. Their location, above 500 m a. s. l. in Belgium, reflects the cold Younger-Dryas climate that have existed at that altitude but it was unclear why similar features did not form on the adjacent Eifel Plateau at the same altitude. We demonstrate here that lithalsas were formed only on weathered quartzitic rocks of the Cambro-Ordovician massif of Stavelot, and probably are associated with local hydrological conditions. © 2010 Gebr. Borntraeaer Verlaasbuchhandluna. Stuttaart. Germany. Source

Heusschen R.,VU University Amsterdam | Heusschen R.,University of Liege | Griffioen A.W.,VU University Amsterdam | Thijssen V.L.,VU University Amsterdam
Biochimica et Biophysica Acta - Reviews on Cancer | Year: 2013

Galectin family members have been shown to exert multiple roles in the context of tumor biology. Several recent findings support a similar multi-faceted role for galectin-9. Galectin-9 expression is frequently altered in cancer as compared to normal tissues. In addition, an increasing amount of evidence suggests that galectin-9 is involved in several aspects of tumor progression, including tumor cell adhesion and survival, immune escape and angiogenesis. Also, galectin-9 shows potential as a prognostic marker and a therapeutic target for several malignancies. In this review we summarize both the established and the emerging roles of galectin-9 in tumor biology and discuss the potential application of galectin-9 in anti-cancer therapy. © 2013 Elsevier B.V. Source

Albiglutide (Eperzan®) is a new once-weekly agonist of Glucagon-Like Peptide-1 (GLP-1) receptors that is indicated in the treatment of type 2 diabetes. Two doses are available, 30 mg and 50 mg, to be injected subcutaneously once a week. It has been extensively evaluated in the HARMONY programme of eight large randomised controlled trials that were performed at different stages of type 2 diabetes, in comparison with placebo or an active comparator. The endocrine and metabolic effects of albiglutide are similar to those of other GLP-1 receptor agonists: stimulation of insulin secretion (incretin effect) and inhibition of glucagon secretion, both in a glucose-dependent manner, retardation of gastric emptying and increase of satiety. These effects lead to a reduction in glycated haemoglobin (HbA1c) levels, combined with a weight reduction. The overall tolerance profile is good. Albiglutide is currently reimbursed in Belgium after failure (HbA1c > 7.5%) of and in combination with a dual therapy with metformin and a sulfonylurea as well as in combination with a basal insulin (with or without oral antidiabetic drugs). To avoid hypoglycaemia, a reduction in the dose of sulfonylurea or insulin may be recommended. A once-weekly administration should increase patient's acceptance of injectable therapy and improve compliance. Source

Mauroy A.,University of Liege | Mezic I.,University of California at Santa Barbara
Physica D: Nonlinear Phenomena | Year: 2015

Sensitivity to initial conditions is usually associated with chaotic dynamics and strange attractors. However, even systems with (quasi)periodic dynamics can exhibit it. In this context we report on the fractal properties of the isochrons of some continuous-time asymptotically periodic systems. We define a global measure of phase sensitivity that we call the phase sensitivity coefficient and show that it is an invariant of the system related to the capacity dimension of the isochrons. Similar results are also obtained with discrete-time systems. As an illustration of the framework, we compute the phase sensitivity coefficient for popular models of bursting neurons, suggesting that some elliptic bursting neurons are characterized by isochrons of high fractal dimensions and exhibit a very sensitive (unreliable) phase response. © 2015 Elsevier B.V. All rights reserved. Source

Boubendir Y.,University Heights | Antoine X.,University of Lorraine | Geuzaine C.,University of Liege
Journal of Computational Physics | Year: 2012

This paper presents a new non-overlapping domain decomposition method for the Helmholtz equation, whose effective convergence is quasi-optimal. These improved properties result from a combination of an appropriate choice of transmission conditions and a suitable approximation of the Dirichlet to Neumann operator. A convergence theorem of the algorithm is established and numerical results validating the new approach are presented in both two and three dimensions. © 2011 Elsevier Inc. Source

Zeisler H.,Medical University of Vienna | Llurba E.,Hospital Universitari Vall dHebron | Chantraine F.,University of Liege | Vatish M.,University of Oxford | And 10 more authors.
New England Journal of Medicine | Year: 2016

BACKGROUND: The ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to placental growth factor (PlGF) is elevated in pregnant women before the clinical onset of preeclampsia, but its predictive value in women with suspected preeclampsia is unclear. METHODS: We performed a prospective, multicenter, observational study to derive and validate a ratio of serum sFlt-1 to PlGF that would be predictive of the absence or presence of preeclampsia in the short term in women with singleton pregnancies in whom preeclampsia was suspected (24 weeks 0 days to 36 weeks 6 days of gestation). Primary objectives were to assess whether low sFlt-1:PlGF ratios (at or below a derived cutoff) predict the absence of preeclampsia within 1 week after the first visit and whether high ratios (above the cutoff) predict the presence of preeclampsia within 4 weeks. RESULTS: In the development cohort (500 women), we identified an sFlt-1:PlGF ratio cutoff of 38 as having important predictive value. In a subsequent validation study among an additional 550 women, an sFlt-1:PlGF ratio of 38 or lower had a negative predictive value (i.e., no preeclampsia in the subsequent week) of 99.3% (95% confidence interval [CI], 97.9 to 99.9), with 80.0% sensitivity (95% CI, 51.9 to 95.7) and 78.3% specificity (95% CI, 74.6 to 81.7). The positive predictive value of an sFlt-1:PlGF ratio above 38 for a diagnosis of preeclampsia within 4 weeks was 36.7% (95% CI, 28.4 to 45.7), with 66.2% sensitivity (95% CI, 54.0 to 77.0) and 83.1% specificity (95% CI, 79.4 to 86.3). CONCLUSIONS: An sFlt-1:PlGF ratio of 38 or lower can be used to predict the short-term absence of preeclampsia in women in whom the syndrome is suspected clinically. Copyright © 2016 Massachusetts Medical Society. Source

Inhibitors of sodium-glucose co-transporter type 2 (SGLT2) are proposed as a novel approach for the management of type 2 diabetes mellitus (T2DM). Several compounds are already available in many countries (dapagliflozin, canagliflozin, empagliflozin and ipragliflozin) and some others are in a late phase of development. The available SGLT2 inhibitors share similar pharmacokinetic characteristics, with a rapid oral absorption, a long elimination half-life allowing once-daily administration, an extensive hepatic metabolism mainly via glucuronidation to inactive metabolites, the absence of clinically relevant drug-drug interactions and a low renal elimination as parent drug. SGLT2 co-transporters are responsible for reabsorption of most (90 %) of the glucose filtered by the kidneys. The pharmacological inhibition of SGLT2 co-transporters reduces hyperglycaemia by decreasing renal glucose threshold and thereby increasing urinary glucose excretion. The amount of glucose excreted in the urine depends on both the level of hyperglycaemia and the glomerular filtration rate. Results of numerous placebo-controlled randomised clinical trials of 12-104 weeks duration have shown significant reductions in glycated haemoglobin (HbA1c), resulting in a significant increase in the proportion of patients reaching HbA1c targets, and a significant lowering of fasting plasma glucose when SGLT2 inhibitors were administered as monotherapy or in addition to other glucose-lowering therapies including insulin in patients with T2DM. In head-to-head trials of up to 2 years, SGLT2 inhibitors exerted similar glucose-lowering activity to metformin, sulphonylureas or sitagliptin. The durability of the glucose-lowering effect of SGLT2 inhibitors appears to be better; however, this remains to be more extensively investigated. The risk of hypoglycaemia was much lower with SGLT2 inhibitors than with sulphonylureas and was similarly low as that reported with metformin, pioglitazone or sitagliptin. Increased renal glucose elimination also assists weight loss and could help to reduce blood pressure. Both effects were very consistent across the trials and they represent some advantages for SGLT2 inhibitors when compared with other oral glucose-lowering agents. The pharmacodynamic response to SGLT2 inhibitors declines with increasing severity of renal impairment, and prescribing information for each SGLT2 inhibitor should be consulted regarding dosage adjustments or restrictions in moderate to severe renal dysfunction. Caution is also recommended in the elderly population because of a higher risk of renal impairment, orthostatic hypotension and dehydration, even if the absence of hypoglycaemia represents an obvious advantage in this population. The overall effect of SGLT2 inhibitors on the risk of cardiovascular disease is unknown and will be evaluated in several ongoing prospective placebo-controlled trials with cardiovascular outcomes. The impact of SGLT2 inhibitors on renal function and their potential to influence the course of diabetic nephropathy also deserve more attention. SGLT2 inhibitors are generally well-tolerated. The most frequently reported adverse events are female genital mycotic infections, while urinary tract infections are less commonly observed and generally benign. In conclusion, with their unique mechanism of action that is independent of insulin secretion and action, SGLT2 inhibitors are a useful addition to the therapeutic options available for the management of T2DM at any stage in the natural history of the disease. Although SGLT2 inhibitors have already been extensively investigated, further studies should even better delineate the best place of these new glucose-lowering agents in the already rich armamentarium for the management of T2DM. Source

Aristizabal Sierra D.,University of Liege | Herrero-Garcia J.,Albanova University Center | Restrepo D.,University of Antioquia | Vicente A.,University of Valencia
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

The ATLAS Collaboration (and also CMS) has recently reported an excess over Standard Model expectations for gauge boson pair production in the invariant mass region 1.8-2.2 TeV. In light of these results, we argue that such a signal might be the first manifestation of the production and further decay of a heavy CP-even Higgs resulting from a type-I two Higgs doublet model. We demonstrate that in the presence of colored vectorlike fermions, its gluon fusion production cross section is strongly enhanced, with the enhancement depending on the color representation of the new fermion states. Our findings show that barring the color triplet case, any QCD "exotic" representation can fit the ATLAS result in fairly large portions of the parameter space. We have found that if the diboson excess is confirmed and this mechanism is indeed responsible for it, then the LHC Run-2 should find (i) a CP-odd scalar with mass below ∼2.3 TeV, (ii) new colored states with masses below ∼2 TeV, (iii) no statistically significant diboson events in the W±Z channel, (iv) events in the triboson channels W±W Z and ZZZ with invariant mass amounting to the mass of the CP-odd scalar. © 2016 American Physical Society. Source

Lemaire R.G.,University of Liege | Lemaire R.G.,rue du Center 46
Knee Surgery, Sports Traumatology, Arthroscopy | Year: 2010

Two hundred and six consecutive total knee arthroplasties were performed in 180 patients with a highly congruous mobile-bearing knee prosthesis. At mean follow-up of 78 months (range: 60-102 months), the outcomes of 181 knees in 158 patients were evaluated using the American Knee Society's Knee and Functional scoring system and Radiological scoring system. Mean values for Knee and Function scores were 92.6 and 81.1, respectively versus 51.8 and 43.4 preoperatively; mean flexion range was 113.6° versus 110.8° preoperatively. There were no cases of bearing dislocation and no radiological signs of loosening or osteolysis. Secondary patella resurfacing was done in 7 of 52 knees in which the patella was not primarily resurfaced. Arthroplasty survival with revision for aseptic loosening as the endpoint was 100% (95% CI: 97.7-100) at 5 years and at 8 years (95% CI: 87.2-100); with revision of the arthroplasty for any reason including one revision for infection as the endpoint, survival was 99.5% (95% CI: 96.9-100) at 5 years and at 8 years (95% CI: 86.9-100). The overall results were satisfactory and compared with those of other mobile-bearing knee prostheses featuring full or partial congruence. No significant differences were noted for range of motion, knee scores and function scores between two subsets of knees that received a bearing allowing only rotation or rotation and 5 mm anteroposterior translation. Longer follow-up is needed to evaluate possible benefits of high congruence and of specific modes of bearing mobility with respect to wear and bony fixation. © 2009 Springer-Verlag. Source

Henrotin Y.,University of Liege
Current rheumatology reports | Year: 2013

The objective of osteoarthritis (OA) treatment is not only control of symptoms (i.e. reducing pain and improving function) but also to preserve joint structure and maintain quality of life. OA management remains challenging. Glucosamine and chondroitin are two compounds available for treatment of OA patients. Taken alone or in combination, they have a good safety profile and a variety of effects. In-vitro and in-vivo experiments have revealed that both compounds induced key intermediates in the OA pathophysiological process. Clinical trials, although providing conflicting and questionable results, report symptomatic and structure-modifying effects for both pharmaceutical-grade compounds. This review will discuss all these subjects and emphasize the importance of the quality of tested compounds for achieving high quality clinical trials. Source

Scheen A.J.,University of Liege
Revue Medicale de Liege | Year: 2015

Individualized therapeutic strategy of dyslipidemias classically relies upon a phenotypic approach. The pattern of lipid profile allows the choice of the best pharmacological option (statin, fibrate) and the patient's clinical risk profile allows the definition of therapeutic goals, especially LDL cholesterol target levels. Dyslipidemias have a major genetic component, which is best illustrated by familial hypercholesterolemia, with its two heterozygous and homozygous forms. There is a huge between-subject variability in the response to lipid-lowering therapies (especially to statins) and ongoing pharmacogenetic and pharmacogenomic studies should help to better understand this inter-individual heterogeneity. The recent discovery of mutations in the PCSK9 gene opened new perspectives regarding the understanding of some forms of familial hypercholesterolemia and led to the development of monoclonal antibodies that selectively inhibit PCSK9. These PCSK9 inhibitors allow, when combined to a statin, drastic reductions in LDL cholesterol concentrations, even when familial hypercholesterolemia is present. They are currently tested in large prospective controlled trials aiming to demonstrate a significant reduction in the residual cardiovascular risk in statin-treated patients. Source

Ceccopieri F.A.,University of Liege | Trentadue L.,University of Parma
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We reconsider the evolution equations for transverse momentum dependent distributions recently proposed by us and recast them in a form which allows the comparison with results recently appeared in the literature. We show under which conditions the obtained results are consistent with each other. © 2014 The Authors. Source

Rigo M.,University of Liege
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010

We survey facts mostly emerging from the seminal results of Alan Cobham obtained in the late sixties and early seventies. We do not attempt to be exhaustive but try instead to give some personal interpretations and some research directions. We discuss the notion of numeration systems, recognizable sets of integers and automatic sequences. We briefly sketch some results about transcendence related to the representation of real numbers. We conclude with some applications to combinatorial game theory and verification of infinite-state systems and present a list of open problems. © 2010 Springer-Verlag Berlin Heidelberg. Source

Geurts P.,University of Liege
Journal of Machine Learning Research | Year: 2011

Given a finite but large set of objects described by a vector of features, only a small subset of which have been labeled as 'positive' with respect to a class of interest, we consider the problem of characterizing the positive class. We formalize this as the problem of learning a feature based score function that minimizes the p-value of a non parametric statistical hypothesis test. For linear score functions over the original feature space or over one of its kernelized versions, we provide a solution of this problem computed by a one-class SVM applied on a surrogate dataset obtained by sampling subsets of the overall set of objects and representing them by their average feature-vector shifted by the average feature-vector of the original sample of positive examples. We carry out experiments with this method on the prediction of targets of transcription factors in two different organisms, E. Coli and S. Cererevisiae. Our method extends enrichment analysis commonly carried out in Bioinformatics and its results outperform common solutions to this problem. Copyright 2011 by the authors. Source

Geris L.,University of Liege | Geris L.,Catholic University of Leuven
International Orthopaedics | Year: 2014

In silico, defined in analogy to in vitro and in vivo as those studies that are performed on a computer, is an essential step in problem-solving and product development in classical engineering fields. The use of in silico models is now slowly easing its way into medicine. In silico models are already used in orthopaedics for the planning of complicated surgeries, personalised implant design and the analysis of gait measurements. However, these in silico models often lack the simulation of the response of the biological system over time. In silico models focusing on the response of the biological systems are in full development. This review starts with an introduction into in silico models of orthopaedic processes. Special attention is paid to the classification of models according to their spatiotemporal scale (gene/protein to population) and the information they were built on (data vs hypotheses). Subsequently, the review focuses on the in silico models used in regenerative orthopaedics research. Contributions of in silico models to an enhanced understanding and optimisation of four key elements - cells, carriers, culture and clinics - are illustrated. Finally, a number of challenges are identified, related to the computational aspects but also to the integration of in silico tools into clinical practice. © 2014 SICOT aisbl. Source

Majerus S.,University of Liege | Majerus S.,Fund for Scientific Research FNRS
Frontiers in Human Neuroscience | Year: 2013

Short-term maintenance of verbal information is a core factor of language repetition, especially when reproducing multiple or unfamiliar stimuli. Many models of language processing locate the verbal short-term maintenance function in the left posterior superior temporo-parietal area and its connections with the inferior frontal gyrus. However, research in the field of short-term memory has implicated bilateral fronto-parietal networks, involved in attention and serial order processing, as being critical for the maintenance and reproduction of verbal sequences. We present here an integrative framework aimed at bridging research in the language processing and short-term memory fields. This framework considers verbal short-term maintenance as an emergent function resulting from synchronized and integrated activation in dorsal and ventral language processing networks as well as fronto-parietal attention and serial order processing networks. To-be-maintained item representations are temporarily activated in the dorsal and ventral language processing networks, novel phoneme and word serial order information is proposed to be maintained via a right fronto-parietal serial order processing network, and activation in these different networks is proposed to be coordinated and maintained via a left fronto-parietal attention processing network. This framework provides new perspectives for our understanding of information maintenance at the non-word-, word- and sentence-level as well as of verbal maintenance deficits in case of brain injury. © 2013 Majerus. Source

Lee R.K.,Cornell University | Mottrie A.,OLV Clinic | Mottrie A.,OLV Vattikuti Robotic Surgery Institute | Payne C.K.,Stanford University | Waltregny D.,University of Liege
European Urology | Year: 2014

Context Abdominal sacrocolpopexy (ASC) represents the superior treatment for apical pelvic organ prolapse (POP) but is associated with increased length of stay, analgesic requirement, and cost compared with transvaginal procedures. Laparoscopic sacrocolpopexy (LSC) and robot-assisted sacrocolpopexy (RSC) may offer shorter postoperative recovery while maintaining equivalent rates of cure. Objective This review evaluates the literature on LSC and RSC for clinical outcomes and complications. Evidence acquisition A PubMed search of the available literature from 1966 to 2013 on LSC and RSC with a follow-up of at least 12 mo was performed. A total of 256 articles were screened, 69 articles selected, and outcomes from 26 presented. A review, not meta-analysis, was conducted due to the quality of the articles. Evidence synthesis LSC has become a mature technique with results from 11 patient series encompassing 1221 patients with a mean follow-up of 26 mo. Mean operative time was 124 min (range: 55-185) with a 3% (range: 0-11%) conversion rate. Objective cure was achieved in 91% of patients, with similar satisfaction rates (92%). Six patient series encompassing 363 patients treated with RSC with a mean follow-up of 28 mo have been reported. Mean operative time was 202 min (range: 161-288) with a 1% (range: 0-4%) conversion rate. Objective cure rate was 94%, with a 95% subjective success rate. Overall, early outcomes and complication rates for both LSC and RSC appeared comparable with open ASC. Conclusions LSC and RSC provide excellent short- to medium-term reconstructive outcomes for patients with POP. RSC is more expensive than LSC. Further studies are required to better understand the clinical performance of RSC versus LSC and confirm long-term efficacy. Patient summary Laparoscopic and robot-assisted sacrocolpopexy represent attractive minimally invasive alternatives to abdominal sacrocolpopexy. They may offer reduced patient morbidity but are associated with higher costs. © 2014 European Association of Urology. Source

Galli E.,University of Rennes 1 | Lancellotti P.,University of Liege | Sengupta P.P.,Cardiac Ultrasound Research and Core Laboratory | Donal E.,University of Rennes 1
JACC: Cardiovascular Imaging | Year: 2014

The assessment of myocardial function in the context of valvular heart disease remains highly challenging. The myocardium deforms simultaneously in 3 dimensions, and global left ventricular (LV) function parameters such as volume and ejection fraction may remain compensated despite the changes in myocardial deformation properties. Current guidelines recommend valve replacement/repair in the presence of symptoms or reduced LV ejection fraction, but the resolution of symptoms or recovery of LV function post-surgery may not be reliably predicted. A wealth of evidence currently suggests that LV dysfunction is frequently subclinical despite normal ejection fraction. It may precede the onset of symptoms and portend a poor outcome due to progressive myocardial remodeling and dysfunction during the postoperative period. The advent of novel tissue-tracking echocardiography techniques has unleashed new opportunities for the clinical identification of early abnormalities in LV function. This review gathers and summarizes current evidence regarding the use of these techniques to assess myocardial deformation in patients with valvular heart disease. (J Am Coll Cardiol Img 2014;7:1151-66) © 2014 by the American College of Cardiology Foundation. Source

Ciarcelluti P.,University of Liege | Foot R.,University of Melbourne
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010

We compute the primordial mirror helium He′ mass fraction emerging from Big Bang nucleosynthesis in the mirror sector of particles in the presence of kinetic mixing between photons and mirror photons. We explore the kinetic mixing parameter (ε) values relevant for cosmology and which are also currently probed by the dark matter direct detection experiments. In particular, we find that for ε ∼ 10- 9, as suggested by the DAMA/Libra and other experiments, a large HeO mass fraction (YHe′ ≈ 90 %) is produced. Such a large value of the primordial He′ mass fraction will have important implications for the mirror dark matter interpretation of the direct detection experiments, as well as for the study of mirror star formation and evolution. © 2010 Elsevier B.V. All rights reserved. Source

Garcia-Gonzalo F.R.,University of California at San Francisco | Phua S.C.,Johns Hopkins University | Roberson E.C.,University of California at San Francisco | Garcia G.,University of California at San Francisco | And 4 more authors.
Developmental Cell | Year: 2015

Primary cilia interpret vertebrate Hedgehog (Hh) signals. Why cilia are essential for signaling is unclear. One possibility is that some forms of signaling require a distinct membrane lipid composition, found at cilia. We found that the ciliary membrane contains a particular phosphoinositide, PI(4)P, whereas a different phosphoinositide, PI(4,5)P2, is restricted to the membrane of the ciliary base. This distribution is created by Inpp5e, a ciliary phosphoinositide 5-phosphatase. Without Inpp5e, ciliary PI(4,5)P2 levels are elevated and Hh signaling is disrupted. Inpp5e limits the ciliary levels of inhibitors of Hh signaling, including Gpr161 and the PI(4,5)P2-binding protein Tulp3. Increasing ciliary PI(4,5)P2 levels or conferring the ability to bind PI(4)P on Tulp3 increases the ciliary localization of Tulp3. Lowering Tulp3 in cells lacking Inpp5e reduces ciliary Gpr161 levels and restores Hh signaling. Therefore, Inpp5e regulates ciliary membrane phosphoinositide composition, and Tulp3 reads out ciliary phosphoinositides to control ciliary protein localization, enabling Hh signaling. © 2015 Elsevier Inc. Source

Li X.,University of Southern California | Lu Z.-L.,University of Southern California | D'Argembeau A.,University of Liege | D'Argembeau A.,Belgian Fund for Scientific Research FRS FNRS | And 2 more authors.
Human Brain Mapping | Year: 2010

The Iowa Gambling Task (IGT) is a sensitive test for the detection of decision-making impairments in several neurological and psychiatric populations. Very few studies have employed the IGT in functional magnetic resonance imaging (fMRI) investigations, in part, because the task is cognitively complex. Here we report a method for exploring brain activity using fMRI during performance of the IGT. Decision-making during the IGT was associated with activity in several brain regions in a group of healthy individuals. The activated regions were consistent with the neural circuitry hypothesized to underlie somatic marker activation and decision-making. Specifically, a neural circuitry involving the dorsolateral prefrontal cortex (for working memory), the insula and posterior cingulate cortex (for representations of emotional states), the mesial orbitofrontal and ventromedial prefrontal cortex (for coupling the two previous processes), the ventral striatum and anterior cingulate/SMA (supplementary motor area) for implementing behavioral decisions was engaged. These results have implications for using the IGT to study abnormal mechanisms of decision making in a variety of clinical populations. © 2009 Wiley-Liss, Inc. Source

Cascales-Minana B.,Montpellier University | Cascales-Minana B.,University of Liege
Review of Palaeobotany and Palynology | Year: 2016

This study aims to approximate an illustrative vision of the apparent temporal dynamics of land plant diversity during the terrestrialization process (i.e., the invasion of the land by plants). This problem has often been addressed through studying the Silurian-Devonian megafossil-based diversity patterns of land plants (embryophytes). However, the inclusion of the dispersed spore fossil record is essential for characterizing the first steps of this process (i.e., Eoembryophytic flora). Consequently, this new study includes both spore taxa and plant megafossils in order to discern the diversity trajectories from the first phases of early land plant diversification until the stabilization of early Carboniferous forests (i.e., Palaeophytic flora). The diversity patterns of the primary recognized plant lineages (i.e., Lycophyta and Euphyllophyta) have been also traced in order to discern the origin of the major fluctuations of plant megafossil-based diversity. Results reveal that while the dispersed spore diversity curve shows a sustained increase towards the end of the Devonian Period - with a first maximum towards the late Silurian - the megafossil embryophyte diversity curve is characterized by a set of sequential ascending peaks at the Pragian (Early Devonian), Givetian (Mid-Devonian), and Visean (Mississippian), with a single significant depletion in the Eifelian (Mid-Devonian). The comparative analysis of the lycophyte and euphyllophyte diversity patterns suggests that the substantial embryophytic diversity changes are driven by diversification within lineages rather than by the rhythm of the appearance of key morphological traits. This evidence (1) advocates for an intrinsic ecological control on the apparent changes in taxic richness and (2) implies that the observed plant diversity dynamics respond to the overlapping of the various expansion phases of the plant lineages involved. © 2015 Elsevier B.V. Source

Debate makes science progress. In the field of endocrine disruption, endocrinology has brought up findings that substantiate a specific perspective on the definition of endocrine disrupting chemicals (EDCs), the role of the endocrine system and the endpoints of hormone and EDC actions among other issues. This paper aims at discussing the relevance of the endocrine perspective with regard to EDC effects on pubertal timing. Puberty involves particular sensitivity to environmental conditions. Reports about the advancing onset of puberty in several countries have led to the hypothesis that the increasing burden of EDCs could be an explanation. In fact, pubertal timing currently shows complex changes since advancement of some manifestations of puberty (e.g. breast development) and no change or delay of others (e.g. menarche, pubic hair development) can be observed. In a human setting with exposure to low doses of tenths or hundreds of chemicals since prenatal life, causation is most difficult to demonstrate and justifies a translational approach using animal models. Studies in rodents indicate an exquisite sensitivity of neuroendocrine endpoints to EDCs. Altogether, the data from both human and animal studies support the importance of concepts derived from endocrinology in the evaluation of EDC effects on puberty. © 2016 S. Karger AG, Basel Copyright © 2016, S. Karger AG. All rights reserved. Source

Multispectral sea surface temperature (SST) algorithms applied to infrared (IR) radiometer data exhibit regional biases due to the intrinsic inability of the SST algorithm to cope with the vast range of atmospheric types, mainly influenced by water vapor and temperature profiles. Deriving a SST correction from simulated brightness temperatures (BTs), obtained by applying a Radiative Transfer Model (RTM) to Numerical Weather Prediction (NWP) atmospheric profiles and first guess SST, is one of the solutions to reduce regional biases. This solution is envisaged in the particular case of Metop-A Advanced Very High Resolution Radiometer (AVHRR) derived SST. Simulated BTs show errors, linked to RTM, atmospheric profiles or guess field errors. We investigated the conditions of adjusting simulated to observed BTs in the particular case of the Mediterranean Sea over almost one year. Our study led to define optimal spatio/temporal averaging parameters of the simulation observation differences, both during day and night, summer and colder season and for two simulation modes: operational (with reduced vertical resolution - 15 levels - NWP atmospheric profiles and two days old analysis used as first guess SST) and delayed (full vertical resolution - 91 levels - and concurrent analysis used as first guess SST). Each BT adjustment has been evaluated by comparing the corresponding corrected AVHRR SST to the AATSR SST that we adopted as validation reference. We obtained an optimized result across all defined conditions and modes for a spatial smoothing of 15. deg and a temporal averaging between 3 and 5. days. Specifically, analyses based on 10. day averages showed that a standard deviation based criterion favors spatial smoothing above 10. deg for all temporal averaging, while a bias based criterion favors shorter temporal averaging during daytime (< 5. days) and higher spatial smoothing (>. 10. deg) for nighttime. This study has shown also the impact of diurnal warming both in deriving BT adjustment and in validation results. © 2013 Elsevier Inc. Source

Pierard L.A.,University of Liege | Carabello B.A.,Baylor College of Medicine
European Heart Journal | Year: 2010

Ischaemic mitral regurgitation is a frequent complication of left ventricular global or regional pathological remodelling due to chronic coronary artery disease. It is not a valve disease but represents the valvular consequences of increased tethering forces (papillary muscles displacement leading to a more apical position of the leaflets and their coaptation point) and reduced closing forces (reduced contractility, dyssynchrony of the papillary muscles, intra-left ventricular dyssynchrony). Although mitral regurgitation has an unloading effect and reduces impedance, the volume overload begets further left ventricular dilatation, increases ventricular wall stress leading to worsened performance. Ischaemic mitral regurgitation is characteristically dynamic: its severity may vary with haemodynamic conditions. Both the severity of ischaemic mitral regurgitation and its dynamic component worsen prognosis. There are numerous possible treatment modalities, but the management of the individual patient remains difficult. Medical therapy is mandatory; revascularization procedures are frequently not sufficient to reduce mitral regurgitation; the role of combined surgical therapy by mitral valve repair is not yet defined in the absence of large randomized trial. Some patients are good candidates for cardiac resynchronization therapy that may reduce the amount of regurgitation. New therapeutic targets are under investigation. © 2010 The Author. Source

De Curtis M.,University of Rome La Sapienza | Rigo J.,University of Liege
Early Human Development | Year: 2012

Although great efforts have been made to improve neonatal nutrition in very low birthweight (VLBW) infants, many do not receive adequate nutrient intake and thus develop extrauterine growth restriction. In order to minimize the interruption of nutrients that occurs at birth, an ". aggressive" nutritional approach has been proposed. Parenteral nutrition, which allows the infant's requirements for growth and development to be met, is indicated in infants for whom feeding via the enteral route is impossible, inadequate, or hazardous. In the last few years, great attention has been given to high amino acid supply in VLBW infants from the first day of life in order to avoid catabolism, establish anabolism, achieve in utero protein accretion rates, and promote linear growth. Whenever possible, enteral feeding should commence with human milk, which is the preferred feeding method for all infants, including those born preterm. In order to meet the unique nutritional requirements of VLBW infants and preserve the singular benefit of breastfeeding, human milk should be fortified to allow adequate growth and bone mineralization. When feeding of preterm infants with human milk is impossible or extremely limited, cow-milk-based formulas for preterm infants must be used. © 2011 Elsevier Ltd. Source

Courtoy A.,University of Liege | Courtoy A.,National Institute of Nuclear Physics, Italy | Goldstein G.R.,Tufts University | Osvaldo Gonzalez Hernandez J.,National Institute of Nuclear Physics, Italy | And 3 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We argue that due to parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions - the generalized transverse momentum distributions - that describes the configuration of an unpolarized quark in a longitudinally polarized nucleon can enter the deeply virtual Compton scattering amplitude only through matrix elements involving a final state interaction. The relevant matrix elements in turn involve light-cone operators projections in the transverse direction, or they appear in the deeply virtual Compton scattering amplitude at twist three. Orbital angular momentum or the spin structure of the nucleon was a major reason for these various distributions and amplitudes to have been introduced. We show that the twist three contributions associated with orbital angular momentum are related to the target-spin asymmetry in deeply virtual Compton scattering, already measured at HERMES. © 2014 The Authors. Source

Rousseau A.-F.,University of Liege | Losser M.-R.,University of Lorraine | Ichai C.,University of Medicine of Nice | Berger M.M.,University of Lausanne
Clinical Nutrition | Year: 2013

Background & aims: Nutrition therapy is a cornerstone of burn care from the early resuscitation phase until the end of rehabilitation. While several aspects of nutrition therapy are similar in major burns and other critical care conditions, the patho-physiology of burn injury with its major endocrine, inflammatory, metabolic and immune alterations requires some specific nutritional interventions. The present text developed by the French speaking societies, is updated to provide evidenced-based recommendations for clinical practice. Methods: A group of burn specialists used the GRADE methodology (Grade of Recommendation, Assessment, Development and Evaluation) to evaluate human burn clinical trials between 1979 and 2011. The resulting recommendations, strong suggestions or suggestions were then rated by the non-burn specialized experts according to their agreement (strong, moderate or weak). Results: Eight major recommendations were made. Strong recommendations were made regarding, 1) early enteral feeding, 2) the elevated protein requirements (1.5-2g/kg in adults, 3g/kg in children), 3) the limitation of glucose delivery to a maximum of 55% of energy and 5mg/kg/h associated with moderate blood glucose (target≤8mmol/l) control by means of continuous infusion, 4) to associated trace element and vitamin substitution early on, and 5) to use non-nutritional strategies to attenuate hypermetabolism by pharmacological (propranolol, oxandrolone) and physical tools (early surgery and thermo-neutral room) during the first weeks after injury. Suggestion were made in absence of indirect calorimetry, to use of the Toronto equation (Schoffield in children) for energy requirement determination (risk of overfeeding), and to maintain fat administration≤30% of total energy delivery. Conclusion: The nutritional therapy in major burns has evidence-based specificities that contribute to improve clinical outcome. © 2013. Source

Dang-Vu T.T.,University of Liege | Dang-Vu T.T.,University of Montreal
NeuroMolecular Medicine | Year: 2012

Recent functional neuroimaging studies have investigated brain activity patterns during sleep in humans, beyond the conventionally defined sleep stages. These works have characterized the neural activations related to the major brain oscillations of sleep, that is, spindles and slow waves during non-rapid-eye-movement sleep and ponto-geniculo-occipital waves during rapid-eye-movement sleep. These phasic events have been found associated with increases of brain activity in specific neural networks, which identify structures involved in the generation of sleep oscillations. Most importantly, these results confirm that, even during the deepest stages of sleep, neuronal network activities are sustained and organized by spontaneous brain oscillations of sleep. The understanding of the neural mechanisms underlying sleep oscillations is fundamental since increasing evidence suggests a pivotal role for these rhythms in the functional properties of sleep. In particular, interactions between the sleeping brain and the surrounding environment are closely modulated by neuronal oscillations of sleep. Functional neuroimaging studies have demonstrated that spindles distort the transmission of auditory information to the cortex, therefore isolating the brain from external disturbances during sleep. In contrast, slow waves evoked by acoustic stimulation-and also termed K-complexes-are associated with larger auditory cortex activation, thus reflecting an enhanced processing of external information during sleep. Future brain imaging studies of sleep should further explore the contribution of neuronal oscillations to the off-line consolidation of memory during sleep. © 2012 Springer Science+Business Media, LLC. Source

Epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. Epigenetics is one of the major mechanisms explaining the "Developmental Origin of Health and Diseases" (DOHaD). Besides genetic background inherited from parents, which confers susceptibility to certain pathologies, epigenetic changes constitute the memory of previous events, either positive or negative, along the life cycle, including at the in utero stage. The later exposition to hostile environment may reveal such susceptibility, with the development of various pathologies, among them numerous chronic complex diseases. The demonstration of such a sequence of events has been shown for metabolic diseases as obesity, metabolic syndrome and type 2 diabetes, cardiovascular disease and cancer. In contrast to genetic predisposition, which is irreversible, epigenetic changes are potentially reversible, thus giving targets not only for prevention, but possibly also for the treatment of certain complex diseases. Source

Dragutan I.,Romanian Academy of Sciences | Dragutan V.,Romanian Academy of Sciences | Demonceau A.,University of Liege
Molecules | Year: 2015

Recent trends in Ru complex chemistry are surveyed with emphasis on the development of anticancer drugs and applications in catalysis, polymers, materials science and nanotechnology. © 2015 by the authors. Source

Raynaud J.-P.,University Pierre and Marie Curie | Rollet J.,Institute Rhone Alpin | Legros J.-J.,University of Liege
BJU International | Year: 2013

What's known on the subject? and What does the study add? • Hypogonadism affects an estimated 2-4 million men in the USA, but only 5% receive treatment. Testosterone replacement therapy reduces the effects of testosterone deficiency on sexual function, mood and energy in hypogonadal patients. Long-term hypogonadism management requires testosterone treatment to restore serum concentrations of testosterone and its active metabolites, within physiological ranges; a testosterone preparation that achieves physiological plasma concentrations without supra-physiological escape is a preferred option. A previous 1-year study European clinical study showed the efficacy and safety of a transdermal testosterone patch (Testopatch®). • The present study shows the long-term (6-year) safety and efficacy of Testopatch in patients with primary or secondary hypogonadism. We show that, over the long-term, Testopatch was associated with no relevant changes in PSA concentration and PSA velocity, or any significant prostate risks (there were no cases of prostate cancer). Objective: • To assess the change in prostate-specific antigen (PSA) concentrations in patients with primary or secondary hypogonadism, receiving transdermal testosterone. Patients and Methods: • This was an interventional, 6-year study, conducted in Urology and Endocrinology centres in Belgium, France, Germany, the Netherlands and Spain. • Participants were primary (48%) or secondary (52%) hypogonadal patients who received two 60 cm2 testosterone patches (Testopatch®), delivering 4.8 mg of testosterone per day, applied every 2 days. • During treatment, total testosterone (TT), dihydrotestosterone, oestradiol and, PSA concentrations were measured in a centralised laboratory every 3 months during the first year, and every 6 months thereafter. Results: • In all, 200 patients [mean (sd) age 41.0 (12.5) years, body weight 82.5 (13.7) kg, height 177.2 (9.3) cm, body mass index 26.2 (3.4) kg/m2] were treated with transdermal testosterone patches. • In all, 161 patients completed the 1-year study and 115 entered into a 5-year study extension; 51 patients completed the sixth year of the study. • The mean baseline concentrations of TT and PSA were 1.4 ng/mL and 0.47 ng/mL, respectively; TT serum concentrations >3 ng/mL were achieved in 85% of patients and fluctuated between 4.4 and 6.0 ng/mL. • At each successive 6-month time point, mean the PSA values were 0.60, 0.67, 0.76, 0.70, 0.61, 0.68, 0.64, 0.71, 0.75, 0.74, 1.01, 0.78, 0.80 ng/mL, respectively. The mean PSA velocity was negligible (0.00-0.03 ng/mL/year) from 30 months to the end of the trial, except for a value of 0.08 at 60 months. Seven patients had a PSA concentration of >4 ng/mL due to a sharp PSA increase. Six of these patients had prostatitis and PSA concentrations returned to previous levels with appropriate treatment. No prostate cancer was reported during the trial. Conclusion: • These data support a strong safety profile for Testopatch, even at the highest registered dosage. © 2013 BJU International. Source

Lorce C.,University Paris - Sud | Lorce C.,University of Liege
Nuclear Physics A | Year: 2014

Exploring the similarities between the Chen et al. approach, where physical and gauge degrees of freedom of the gauge potential are explicitly separated, and the background field method, we provide an alternative point of view to the proton spin decomposition issue. We show in particular that the gauge symmetry can be realized in two different ways, and discuss the relations between the concepts of path dependence, Stueckelberg dependence and background dependence. Finally, we argue that path/Stueckelberg/background-dependent decompositions of the proton spin are in principle measurable and therefore physically meaningful. © 2014 Elsevier B.V. Source

Lorce C.,University Paris - Sud | Lorce C.,University of Liege
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We investigate the correlations between the quark spin and orbital angular momentum inside the nucleon. Similarly to the Ji relation, we show that these correlations can be expressed in terms of specific moments of measurable parton distributions. This provides a whole new piece of information about the partonic structure of the nucleon. © 2014. Source

Zecevic J.,University Utrecht | Gommes C.J.,University of Liege | Friedrich H.,TU Eindhoven | Dejongh P.E.,University Utrecht | Dejong K.P.,University Utrecht
Angewandte Chemie - International Edition | Year: 2012

Quantitative insight into the three-dimensional morphology of complex zeoliteY mesopore networks was achieved by combining electron tomography and image processing. Properties could be studied that are not measurable by other techniques, such as the size distribution of the intact microporous domains. This has great relevance in descriptions of the molecular diffusion through zeolite crystals and, hence, catalytic activity and selectivity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Gregoire M.,University of Liege | Soetaert K.,Netherlands Institute of Ecology
Ecological Modelling | Year: 2010

Carbon, nitrogen, oxygen and sulfide budgets are derived for the Black Sea water column from a coupled physical-biogeochemical model. The model is applied in the deep part of the sea and simulates processes over the whole water column including the anoxic layer that extends from ≃115. m to the bottom (≃2000. m). The biogeochemical model involves a refined representation of the Black Sea foodweb from bacteria to gelatinous carnivores. It includes notably a series of biogeochemical processes typical for oxygen deficient conditions with, for instance, bacterial respiration using different types of oxidants (i.e denitrification, sulfate reduction), the lower efficiency of detritus degradation, the ANAMMOX (ANaerobic AMMonium OXidation) process and the occurrence of particular redox reactions. The model has been calibrated and validated against all available data gathered in the Black Sea TU Ocean Base and this exercise is described in Gregoire et al. (2008). In the present paper, we focus on the biogeochemical flows produced by the model and we compare model estimations with the measurements performed during the R.V. KNORR expedition conducted in the Black Sea from April to July 1988 (Murray and the Black Sea Knorr Expedition, 1991). Model estimations of hydrogen sulfide oxidation, metal sulfide precipitation, hydrogen sulfide formation in the sediments and water column, export flux to the anoxic layer and to the sediments, denitrification, primary and bacterial production are in the range of field observations.With a simulated Gross Primary Production (GPP) of 7.9molCm-2year-1 and a Community Respiration (CR) of 6.3molCm-2year-1, the system is net autotrophic with a Net Community Production (NCP) of 1.6molCm-2year-1. This NCP corresponds to 20% of the GPP and is exported to the anoxic layer. In order to model Particulate Organic Matter (POM) fluxes to the bottom and hydrogen sulfide profiles in agreement with in situ observations, we have to consider that the degradation of POM in anoxic conditions is less efficient that in oxygenated waters as it has often been observed (see discussion in Hedges et al., 1999). The vertical POM profile produced by the model can be fitted to the classic power function describing the oceanic carbon rate (CR=Z-α) using an attenuation coefficient α of 0.36 which is the value proposed for another anoxic environment (i.e. the Mexico Margin) by Devol and Hartnett (2001). Due to the lower efficiency of detritus degradation in anoxic conditions and to the aggregation of particles that enhanced the sinking, an important part of the export to the anoxic layer (i.e. 33%, 0.52molCm-2year-1) escapes remineralization in the water column and reaches the sediments. Therefore, sediments are active sites of sulfide production contributing to 26% of the total sulfide production.In the upper layer, the oxygen dynamics is mainly governed by photosynthesis and respiration processes as well as by air-sea exchanges ≃71% of the oxygen produced by phytoplankton (photosynthesis+nitrate reduction) is lost through respiration, ≃21% by outgasing to the atmosphere, ≃5% through nitrification and only ≃2% in the oxidation of reduced components (e.g. Mn2+, Fe2+, H2S).The model estimates the amount of nitrogen lost through denitrification at 307mmolNm-2year-1 that can be partitioned into a loss of ≃55% through the use of nitrate for the oxidation of detritus in low oxygen conditions, ≃40% in the ANAMMOX process and the remaining ≃5% in the oxidation of reduced substances by nitrate.In agreement with data analysis performed on long time series collected since the 1960s (Konovalov and Murray, 2001), the sulfide and nitrogen budgets established for the anoxic layer are not balanced in response to the enhanced particle fluxes induced by eutrophication: the NH4 and H2S concentrations increase. © 2010 Elsevier B.V. Source

Pottel H.,Catholic University of Leuven | Hoste L.,Catholic University of Leuven | Delanaye P.,University of Liege
Pediatric Nephrology | Year: 2015

Results: Based on our literature search, the inclusion of children in published CKD studies has been based on cut-off values for eGFR of >60 mL/min/1.73 m2. The lower reference limits for mGFR far exceed this adult threshold. Using eGFR values calculated using Scr-based formulas, we found that abnormal Scr levels in children already correspond to eGFR values that are below a cut-off of 75 mL/min/1.73 m2.Methods: Based on a literature search, we evaluated inclusion criteria for eGFR in clinical trials or research studies on CKD for children. We also collected information on direct measurements of GFR (mGFR) in children and adolescents, with the aim to estimate the normal reference range for GFR. Using serum creatinine (Scr) normal reference values and Scr-based eGFR-equations, we also evaluated the correspondence between Scr normal reference values and (e)GFR normal reference values.Conclusions: Abnormal GFR in children, adolescents and young adults starts below 75 mL/min/1.73 m2, and as abnormality is a sign of disease, we recommend referring children, adolescents and young adults with an (e)GFR of <75 mL/min/1.73 m2 for further clinical assessment.Background: The chronic kidney disease (CKD) classification system for children is similar to that for adults, with both mainly based on estimated glomerular filtration rate (eGFR) combined with fixed cut-off values. The main cut-off eGFR value used to define CKD is 60 mL/min/1.73 m2, a value that is also applied for children older than 2 years of age, adolescents and young adults. © 2014, IPNA. Source

Boucenna S.M.,National Institute of Nuclear Physics, Italy | Valle J.W.F.,University of Valencia | Vicente A.,University of Valencia | Vicente A.,University of Liege
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

Neutrino oscillations are solidly established, with a hint of CP violation just emerging. Similarly, there are hints of lepton universality violation in b→s transitions at the level of 2.6σ. By assuming that the unitary transformation between weak and mass charged leptons equals the leptonic mixing matrix measured in neutrino oscillation experiments, we predict several lepton flavor violating (LFV) B meson decays. We are led to the tantalizing possibility that some LFV branching ratios for B decays correlate with the leptonic CP phase δ characterizing neutrino oscillations. Moreover, we also consider implications for ℓi→ℓjℓkℓk decays. © 2015 The Authors. Source

Belkacem K.,University of Liege
Lecture Notes in Physics | Year: 2011

Solar gravity modes are mainly trapped inside the radiative region and are then able to provide information on the properties of the central part of the Sun granulation. However, there is no consensus on the detection of solar gravity modes which remains a major challenge. In this paper, we discuss the underlying driving and damping processes of solar g modes, and review the quantitative estimates of their amplitudes. This issue is important since a theoretical determination of mode amplitudes may help to design the track for gravity modes. © 2011 Springer-Verlag Berlin Heidelberg. Source

Grauert A.,University College London | Engel D.,University of Liege | Ruiz A.J.,University College London
Journal of Physiology | Year: 2014

Zinc actions on synaptic transmission span the modulation of neurotransmitter receptors, transporters, activation of intracellular cascades and alterations in gene expression. Whether and how zinc affects inhibitory synaptic signalling in the dentate gyrus remains largely unexplored. We found that mono- and di-synaptic GABAergic inputs onto dentate granule cells were reversibly depressed by exogenous zinc application and enhanced by zinc chelation. Blocking T-type Ca2+ channels prevented the effect of zinc chelation. When recording from dentate fast-spiking interneurones, zinc chelation facilitated T-type Ca2+ currents, increased action potential half-width and decreased spike threshold. It also increased the offset of the input-output relation in a manner consistent with enhanced excitability. In granule cells, chelation of zinc reduced the time window for the integration of glutamatergic inputs originating from perforant path synapses, resulting in reduced spike transfer. Thus, zinc-mediated modulation of dentate interneurone excitability and GABA release regulates information flow to local targets and hippocampal networks. © 2013 The Physiological Society. Source

Figueroa M.,University of Liege
PloS one | Year: 2013

The computational protein design protocol Rosetta has been applied successfully to a wide variety of protein engineering problems. Here the aim was to test its ability to design de novo a protein adopting the TIM-barrel fold, whose formation requires about twice as many residues as in the largest proteins successfully designed de novo to date. The designed protein, Octarellin VI, contains 216 residues. Its amino acid composition is similar to that of natural TIM-barrel proteins. When produced and purified, it showed a far-UV circular dichroism spectrum characteristic of folded proteins, with α-helical and β-sheet secondary structure. Its stable tertiary structure was confirmed by both tryptophan fluorescence and circular dichroism in the near UV. It proved heat stable up to 70°C. Dynamic light scattering experiments revealed a unique population of particles averaging 4 nm in diameter, in good agreement with our model. Although these data suggest the successful creation of an artificial α/β protein of more than 200 amino acids, Octarellin VI shows an apparent noncooperative chemical unfolding and low solubility. Source