Universitelibre Of Bruxelles Ulb

Brussels, Belgium

Universitelibre Of Bruxelles Ulb

Brussels, Belgium
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Morabito A.,Universitelibre Of Bruxelles Ulb | Steimes J.,Universitelibre Of Bruxelles Ulb | Bontems O.,Agence Intercommunale IDETA Scrl | Al Zohbi G.,Universitelibre Of Bruxelles Ulb | Hendrick P.,Universitelibre Of Bruxelles Ulb
Journal of Physics: Conference Series | Year: 2017

Its maturity makes pumped hydro energy storage (PHES) the most used technology in energy storage. Micro-hydro plants (<100 kW) are globally emerging due to further increases in the share of renewable electricity production such as wind and solar power. This paper presents the design of a micro-PHES developed in Froyennes, Belgium, using a pump as turbine (PaT) coupled with a variable frequency driver (VFD). The methods adopted for the selection of the most suitable pump for pumping and reverse mode are compared and discussed. Controlling and monitoring the PaT performances represent a compulsory design phase in the analysis feasibility of PaT coupled with VFD in micro PHES plant. This study aims at answering technical research aspects of μ-PHES site used with reversible pumps. © Published under licence by IOP Publishing Ltd.

Espion B.,Universitelibre Of Bruxelles Ulb | Provost M.,Universitelibre Of Bruxelles Ulb | Bastin O.,Universitelibre Of Bruxelles Ulb | Bouillard P.,Universitelibre Of Bruxelles Ulb | Bouillard P.,Nazarbayev University
Proceedings of the Institution of Civil Engineers: Bridge Engineering | Year: 2015

The crossing of rivers in Katanga (Democratic Republic of Congo) by railway lines in the 1920s and 1930s gave Belgian engineers and contractors the opportunity to build record spans for railway bridges. The crossing of the Lualaba River at Bukama consists of four Vierendeel steel girders each with a 62 m span, which were the largest of their type at the time of their erection in 1925. The crossing of the Lualaba at Kongolo, built in 1937-1939, required a 495 m long reinforced concrete continuous beam bridge with 14 spans, the largest measuring 70 m. It was the first significant concrete beam bridge constructed with a travelling gantry supporting movable formwork. The crossing of the Lukaga River (1938-1939) is a three-span concrete bridge with the 70 m long central span built using the cantilever method, which makes this bridge the oldest of its type in the world. This paper highlights the landmark characteristics of these forgotten bridges.

Fiorini S.,Universitelibre Of Bruxelles Ulb | Massar S.,Universitelibre Of Bruxelles Ulb | Patra M.K.,Universitelibre Of Bruxelles Ulb | Tiwary H.R.,Charles University
Journal of Physics A: Mathematical and Theoretical | Year: 2015

Generalized probabilistic theories (GPT) provide a general framework that includes classical and quantum theories. It is described by a cone C and its dual C∗. We show that whether some one-way communication complexity problems can be solved within a GPT is equivalent to the recently introduced cone factorization of the corresponding communication matrix M. We also prove an analogue of Holevo's theorem: when the cone C is contained in Rn, the classical capacity of the channel realized by sending GPT states and measuring them is bounded by log n. Polytopes and optimising functions over polytopes arise in many areas of discrete mathematics. A conic extension of a polytope is the intersection of a cone C with an affine subspace whose projection onto the original space yields the desired polytope. Extensions of polytopes can sometimes be much simpler geometric objects than the polytope itself. The existence of a conic extension of a polytope is equivalent to that of a cone factorization of the slack matrix of the polytope, on the same cone. We show that all 0/1 polytopes whose vertices can be recognized by a polynomial size circuit, which includes as a special case the travelling salesman polytope and many other polytopes from combinatorial optimization, have small conic extension complexity when the cone is the completely positive cone. Using recent exponential lower bounds on the linear extension complexity of polytopes, this provides an exponential gap between the communication complexity of GPT based on the completely positive cone and classical communication complexity, and a conjectured exponential gap with quantum communication complexity. Our work thus relates the communication complexity of generalizations of quantum theory to questions of mainstream interest in the area of combinatorial optimization. © 2015 IOP Publishing Ltd.

Desir J.,Universitelibre Of Bruxelles Ulb | Sznajer Y.,Hopital Erasme ULB | Sznajer Y.,Clinical Genetics Unit | Depasse F.,Hopital Erasme ULB | And 5 more authors.
European Journal of Human Genetics | Year: 2010

The latent TGFΒ-binding proteins (LTBPs) and fibrillins are a superfamily of large, multidomain proteins with structural and TGFΒ-signalling roles in the extracellular matrix. Their importance is underscored by fibrillin-1 mutations responsible for Marfan syndrome, but their respective roles are still incompletely understood. We report here on two families where children from healthy, consanguineous parents, presented with megalocornea and impaired vision associated with small, round, dislocated lenses (microspherophakia and ectopia lentis) and myopia, as well as a high-arched palate, and, in older children, tall stature with an abnormally large arm span over body height ratio, that is, associated features of Marfan syndrome. Glaucoma was not present at birth, but was diagnosed in older children. Whole genome homozygosity mapping followed by candidate gene analysis identified homozygous truncating mutations of LTBP2 gene in patients from both families. Fibroblast mRNA analysis was consistent with nonsense-mediated mRNA decay, with no evidence of mutated exon skipping. We conclude that biallelic null LTBP2 mutations cause the ocular phenotype in both families and could lead to Marfan-like features in older children. We suggest that intraocular pressures should be followed-up in young children with an ocular phenotype consisting of megalocornea, spherophakia and/or lens dislocation, and recommend LTBP2 gene analysis in these patients. © 2010 Macmillan Publishers Limited All rights reserved.

Darcis G.,Universitelibre Of Bruxelles Ulb | Darcis G.,University of Liège | Van Driessche B.,Universitelibre Of Bruxelles Ulb | Van Lint C.,Universitelibre Of Bruxelles Ulb
Current Opinion in HIV and AIDS | Year: 2016

Purpose of review The 'shock and kill' strategy consists of activating HIV-1 expression to allow latently infected cells to die from viral cytopathic effects or host cytolytic immune effectors. This strategy relies on small molecules, called latency reversing agents, which activate HIV transcription. Recent findings Several mechanisms operating at the transcriptional level are involved in the establishment and maintenance of HIV-1 latency, including the absence of crucial inducible host transcription factors, epigenetic silencing, and the sequestration of the positive transcription elongation factor B. Progresses made toward the understanding of the molecular mechanisms of HIV-1 transcriptional repression have led to the identification of latency reversing agents that activate HIV transcription, such as histone deacetylase inhibitors or protein kinase C agonists. Multiple studies have recently pointed interesting ways to optimize the shock strategy by using combinations of latency reversing agents with an appropriate time schedule. Summary Combining latency reversing agents appears as one potential strategy for therapy against HIV-1 latency. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Allagnat F.,Free University of Colombia | Cunha D.,Free University of Colombia | Moore F.,Free University of Colombia | Vanderwinden J.M.,Universitelibre Of Bruxelles Ulb | And 2 more authors.
Cell Death and Differentiation | Year: 2011

Pancreatic Β-cell apoptosis is a key feature of diabetes mellitus and the mitochondrial pathway of apoptosis is a major mediator of Β-cell death. We presently evaluated the role of the myeloid cell leukemia sequence 1 (Mcl-1), an antiapoptotic protein of the Bcl-2 family, in Β-cells following exposure to well-defined Β-cell death effectors, for example, pro-inflammatory cytokines, palmitate and chemical endoplasmic reticulum (ER) stressors. All cytotoxic stresses rapidly and preferentially decreased Mcl-1 protein expression as compared with the late effect observed on the other antiapoptotic proteins, Bcl-2 and Bcl-xL. This was due to ER stress-mediated inhibition of translation through eIF2α phosphorylation for palmitate and ER stressors and through the combined action of translation inhibition and JNK activation for cytokines. Knocking down Mcl-1 using small interference RNAs increased apoptosis and caspase-3 cleavage induced by cytokines, palmitate or thapsigargin, whereas Mcl-1 overexpression partly prevented Bax translocation to the mitochondria, cytochrome c release, caspase-3 cleavage and apoptosis induced by the Β-cell death effectors. Altogether, our data suggest that Mcl-1 downregulation is a crucial event leading to Β-cell apoptosis and provide new insights into the mechanisms linking ER stress and the mitochondrial intrinsic pathway of apoptosis. Mcl-1 is therefore an attractive target for the design of new strategies in the treatment of diabetes. © 2011 Macmillan Publishers Limited All rights reserved.

Herchuelz A.,Universitelibre Of Bruxelles Ulb | Nguidjoe E.,Universitelibre Of Bruxelles Ulb | Jiang L.,Universitelibre Of Bruxelles Ulb | Pachera N.,Universitelibre Of Bruxelles Ulb
Diabetes, Obesity and Metabolism | Year: 2012

Ca2+ extrusion from the β-cell is mediated by two processes the Na/Ca exchanger (NCX) and the plasma membrane Ca2+-ATPase (PMCA). Gain of function studies show that overexpression of NCX or PMCA leads to endoplasmic reticulum (ER) Ca2+ depletion with subsequent ER stress, decrease in β-cell proliferation and β-cell death by apoptosis. Interestingly, chronic exposure to cytokines or high free fatty acid concentrations also induce ER Ca2+ depletion and β-cell death in diabetes. Loss of function studies show, on the contrary, that heterozygous inactivation of NCX1 (Ncx1+/-) leads to an increase in β-cell function (insulin production and release), and a fivefold increase in both β-cell mass and proliferation. The mutation also increases β-cell resistance to hypoxia, and Ncx1+/- islets show a two to four times higher rate of diabetes cure than Ncx1+/+ islets when transplanted in diabetic animals. Thus, down-regulation of the Na/Ca exchanger leads to various changes in β-cell function that are opposite to the major abnormalities seen in diabetes. This provides a unique model for the prevention and treatment of β-cell dysfunction in diabetes and following islet transplantation. © 2012 Blackwell Publishing Ltd.

Pironio S.,Universitelibre Of Bruxelles Ulb
Journal of Physics A: Mathematical and Theoretical | Year: 2014

The correlations that admit a local hidden-variable model are described by a family of polytopes, whose facets are the Bell inequalities. The Clauser-Home-Shimony-Holt (CHSH) inequality is the simplest such Bell inequality and is a facet of every Bell polytope. We investigate for which Bell polytopes the CHSH inequality is also the unique (non-trivial) facet. We prove that the CHSH inequality is the unique facet for all bipartite polytopes where at least one party has a binary choice of dichotomic measurements, irrespective of the number of measurement settings and outcomes for the other party. Based on numerical results, we conjecture that it is also the unique facet for all bipartite polytopes involving two measurements per party where at least one measurement is dichotomic. Finally, we remark that these two situations can be the only ones for which the CHSH inequality is the unique facet, i.e., any polytope that does not correspond to one of these two cases necessarily has facets that are not of the CHSH form. As a byproduct of our approach, we derive a new family of facet inequalities. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to '50 years of Bell's theorem'. © 2014 IOP Publishing Ltd.

Brenguier R.,Universitelibre Of Bruxelles Ulb | Raskin J.-F.,Universitelibre Of Bruxelles Ulb
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

In this paper, we study the set of thresholds that the protagonist can force in a zero-sum two-player multidimensional mean-payoff game. The set of maximal elements of such a set is called the Pareto curve, a classical tool to analyze trade-offs. As thresholds are vectors of real numbers in multiple dimensions, there exist usually an infinite number of such maximal elements. Our main results are as follow. First, we study the geometry of this set and show that it is definable as a finite union of convex sets given by linear inequations. Second, we provide a Σ2P algorithm to decide if this set intersects a convex set defined by linear inequations, and we prove the optimality of our algorithm by providing a matching complexity lower bound for the problem. Furthermore, we show that, under natural assumptions, i.e. fixed number of dimensions and polynomially bounded weights in the game, the problem can be solved in deterministic polynomial time. Finally, we show that the Pareto curve can be effectively constructed, and under the former natural assumptions, this construction can be done in deterministic polynomial time. © Springer International Publishing Switzerland 2015.

Brohee S.,Universitelibre Of Bruxelles Ulb | Janky R.,Universitelibre Of Bruxelles Ulb | Abdel-Sater F.,Universitelibre Of Bruxelles Ulb | Vanderstocken G.,Universitelibre Of Bruxelles Ulb | And 2 more authors.
Nucleic Acids Research | Year: 2011

With the growing number of available microbial genome sequences, regulatory signals can now be revealed as conserved motifs in promoters of orthologous genes (phylogenetic footprints). A next challenge is to unravel genome-scale regulatory networks. Using as sole input genome sequences, we predicted cis-regulatory elements for each gene of the yeast Saccharomyces cerevisiae by discovering over-represented motifs in the promoters of their orthologs in 19 Saccharomycetes species. We then linked all genes displaying similar motifs in their promoter regions and inferred a co-regulation network including 56 919 links between 3171 genes. Comparison with annotated regulons highlights the high predictive value of the method: a majority of the top-scoring predictions correspond to already known co-regulations. We also show that this inferred network is as accurate as a co-expression network built from hundreds of transcriptome microarray experiments. Furthermore, we experimentally validated 14 among 16 new functional links between orphan genes and known regulons. This approach can be readily applied to unravel gene regulatory networks from hundreds of microbial genomes for which no other information is available except the sequence. Long-term benefits can easily be perceived when considering the exponential increase of new genome sequences. © 2011 The Author(s).

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