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See detailRisk of emergence of a hyperpathogenic bovine leukemia virus by mutation of a single envelope N-linked glycosylation site
De Brogniez, Alix ULg; Bouzar, Amel-Baya; Jacques, Jean-Rock ULg et al

Poster (2015, February 11)

- Introduction : Pathogens have co-evolved with their host to ensure efficient replication and transmission without inducing excessive pathogenicity that would indirectly impair their persistence. This is ... [more ▼]

- Introduction : Pathogens have co-evolved with their host to ensure efficient replication and transmission without inducing excessive pathogenicity that would indirectly impair their persistence. This is exemplified by the bovine leukemia virus (BLV) system in which lymphoproliferative disorders develop in ruminants after latency periods of several years. Infection of sheep and cattle with BLV is a model system for the related human T-lymphotropic virus type 1 (HTLV-1) responsible for Adult T-cell Leukemia (ATL). - Aims : The goal of this work is to investigate the role of N-glycans of the viral envelope protein during viral replication and pathogenesis. - Methods and results : Using glycosylation inhibitors and lectins, we showed that N-glycosylation is involved in viral infection (i.e. cell-to-cell fusion). Using reverse genetics of an infectious molecular provirus, we next demonstrated that a particular N-linked envelope glycosylation site (N230) limits viral replication and pathogenicity in vitro and in vivo. We have thus generated a viral mutant that is more pathogenic than the wild type strain. - Conclusions : To our knowledge, this is the first time that a hyperpathogenic BLV has been identified. This unexpected observation has important consequences in terms of disease control and managing. Indeed, during evolution, pathogens and their hosts should achieve an equilibrium allowing the coexistence of the two species. Occurrence of this particular mutation may thus represent a potential threat associated with emergence of hyperpathogenic BLV strains and possibly of new variants of the related HTLV-1. [less ▲]

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See detailMener pratiquement ses entretiens: retour d'expériences
Parotte, Céline ULg

Learning material (2015)

Trucs et astuces pour mener pratiquement ses entretiens qualitatifs. Pratiquement, cette présentation a pour objectif de mettre l'étudiant en situation concrète: que faire? à quoi penser? comment me ... [more ▼]

Trucs et astuces pour mener pratiquement ses entretiens qualitatifs. Pratiquement, cette présentation a pour objectif de mettre l'étudiant en situation concrète: que faire? à quoi penser? comment me préparer? [less ▲]

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See detailCheckpoints modulation by the human T-lymphotropic virus type 1 (HTLV-1) Tax protein : towards new therapeutic approaches
Carpentier, Alexandre ULg; Barez, Pierre-Yves ULg; Boxus, Mathieu et al

Poster (2015, February 11)

HTLV-1 infects approximately 20 million people worldwide and causes several diseases. This virus is responsible for the adult T-cell leukemia (ATL) and for a chronic neuropathology (TSP/HAM). There is ... [more ▼]

HTLV-1 infects approximately 20 million people worldwide and causes several diseases. This virus is responsible for the adult T-cell leukemia (ATL) and for a chronic neuropathology (TSP/HAM). There is currently no satisfactory treatment for these diseases. Among the proteins encoded by HTLV-1, Tax appears to play an important role in the mechanisms leading to pathogenicity. We are interested in the mechanisms of cell transformation by HTLV-1 and more particularly in the interplay between the viral Tax oncoprotein and the DNA damage response (DDR). We demonstrate that transient expression of Tax results in DNA damage, cell cycle arrest and activation of the ATM-Chk2-p53 axis of the DDR. In fibroblasts, cell cycle arrest occurs at the G1 and G2 phases depending on the p53 background. Despite Tax expression hampers cell cycle progression, neither pro-apoptotic nor pro-senescent effects are observed. In contrast, HTLV-1 infected lymphocytes proliferate continuously and appear to be adapted to the checkpoints. This mechanism allows infected lymphocytes to proliferate despite the presence of genomic lesions. Those cells might thus rely on effective DNA repair mechanisms. Indeed, we show that Tax expressing cells activate the error free repair mechanism homologous recombination (HR). Inhibition of ATM, involved in DDR and DNA repair by HR, impedes Tax-mediated cellular transformation. Depending on these observations, we propose a novel therapeutic approach based on the principle of synthetic lethality. [less ▲]

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See detailReprogramming of replication origin firing and checkpoint adaptation in adult T-cell leukemia
Carpentier, Alexandre ULg; Barez, Pierre-Yves ULg; Boxus, Mathieu et al

Conference (2015, February 11)

Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus that infects about twenty million individuals worldwide. HTLV-1 is the causative agent of different diseases among which the most common are the ... [more ▼]

Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus that infects about twenty million individuals worldwide. HTLV-1 is the causative agent of different diseases among which the most common are the adult T-cell leukemia (ATL) and a neurodegenerative disorder called HAM/TSP (Human associated myelopathy/ Tropical spastic paraparesis). A key parameter of HTLV-1 pathogenesis is faster replication of provirus-carrying lymphocytes allowing clonal expansion of infected cell populations. The virally-encoded Tax oncoprotein plays an essential role in this process by interacting with DNA replication origins and accelerating S phase progression. By reprogramming the timing of origin firing, Tax also creates a replicative stress leading to DNA double strand breaks. This mechanism further triggers the DNA damage response (DDR) that induces cell cycle arrest and initiates either apoptosis or senescence. However, HTLV-1 infected cells have developed strategies to interfere with the DDR and are adapted to checkpoint control. These cells are thus able to proliferate despite occurrence of DNA damage. Based on these observations, we now propose a novel therapeutic approach based on the principle of synthetic lethality. [less ▲]

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See detailEnvironmental / climatic changes & the people ...
Ozer, Pierre ULg

Scientific conference (2015, February 11)

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See detailLes premiers enseignements de l'enquête auprès des élevages laitiers sur leurs évolutions technico-économiques
Beckers, Yves ULg; Vanwindekens, Frédéric ULg; Wyzen, Benoît et al

in Carrefour des Productions animales, 20ème édition "L'exploitation laitière wallonne de demain : du point de vue des acteurs aux propositions de la reccherche" (2015, February 11)

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See detailL'exploitation laitière de demain : présentation de l'enquête
Beckers, Yves ULg

Conference (2015, February 11)

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See detailL'exploitation laitière de demain : conclusions
Beckers, Yves ULg

Conference (2015, February 11)

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See detailTen years of Martian nitric oxide nightglow observations
Stiepen, Arnaud ULg; Gérard, Jean-Claude ULg; Gagné, Marie-Eve et al

in Geophysical Research Letters (2015)

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See detailC'est la faute à l'Europe !
Grandjean, Geoffrey ULg

Conference given outside the academic context (2015)

Nombreux sont les dirigeants politiques et les citoyens qui considèrent que l’Union européenne est responsable de la situation politique et économique actuelle. L’exposé vise à interroger ces discours et ... [more ▼]

Nombreux sont les dirigeants politiques et les citoyens qui considèrent que l’Union européenne est responsable de la situation politique et économique actuelle. L’exposé vise à interroger ces discours et à comprendre la place et le rôle des institutions européennes. Il permet surtout de relativiser ces discours en ciblant précisément les marges de manœuvre de l’Union européenne. [less ▲]

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See detailCognitive remediation of autobiographical memory in schizophrenia and its relation with depressive mood.
Blairy, Sylvie ULg

Scientific conference (2015, February 09)

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See detailCritique des données statistiques 'macro' disponibles dans les institutions internationales
Ozer, Pierre ULg

Scientific conference (2015, February 09)

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See detailQuestion d'actualité en environnement : un cours intégrateur/ transversal qui fait sens pour les étudiants de Bac1 en sciences Bio-ingénieur
Colaux, Catherine ULg

Scientific conference (2015, February 09)

Lors de son entrée à l'université l'étudiant primant est souvent décontenancé. Tous les changements auxquels il doit faire face (organisation des cours, exigences des enseignants, nouveau contexte social ... [more ▼]

Lors de son entrée à l'université l'étudiant primant est souvent décontenancé. Tous les changements auxquels il doit faire face (organisation des cours, exigences des enseignants, nouveau contexte social etc.) le conduisent quelques fois à douter, allant même quelques fois jusqu'à remettre en question son choix d'orientation. Les étudiants Bioingénieurs de Gembloux Agro Bio Tech ne dérogent pas à cette règle. Il nous paraissait donc primordial de proposer à l'horaire de première année un cours intégrateur qui puisse conforter les étudiants dans leur choix de filière mais plus encore, qui puisse impacter leur perception de valeur, souvent négative, de certains de leurs enseignements. Un des objectifs de ce cours est donc de démontrer à nos étudiants, en traitant un sujet d'actualité en environnement que leurs cours de mathématique, physique, chimie etc. sont nécessaires à leur formation de bioingénieurs. Ce cours se veut également innovant puisqu'il sortira du canevas ex-cathedra classiquement appliqué en première année et proposera aux étudiants un travail en petits groupes et essentiellement en ligne. Ce sera l'occasion d'aborder avec eux en tout début de cursus ces compétences transversales qui prennent de plus en plus de place dans nos formations. [less ▲]

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See detailImaging the mechanisms involved in abdominal aortic aneurysms rupture; a step towards patient-specific risk assessment
NCHIMI LONGANG, Alain ULg

Doctoral thesis (2015)

Introduction The general context of this dissertation is to evaluate patient-specifi c approaches to the risk of rupture of abdominal aortic aneurysm (AAA), using imaging techniques with ability to assess ... [more ▼]

Introduction The general context of this dissertation is to evaluate patient-specifi c approaches to the risk of rupture of abdominal aortic aneurysm (AAA), using imaging techniques with ability to assess biological processes. Following a thorough description of available imaging techniques, our work is divided in two main research objectives, namely: (i) to provide greater clinical value to existing but unproven imaging concepts, and (ii) to suggest new concepts for improved AAA risk of rupture assessment. Methods The fi rst research objective evaluated how far imaging biological activities using 18F-Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) and modeling wall stress using fi nite element simulations (FES) may help clinical decisionmaking in patients with AAA, and what would be their incremental value as compared to diameter-based patient management algorithms. On a patient basis, clinical outcomes were evaluated with regard to FDG PET and FES signaling. Further, the concept of AAA risk-equivalent diameter using FES was described and retrospectively validated using data from large multicenter trials. The second research objective included the assessment of the biological activities of the intraluminal thrombus (ILT) and the demonstration of its deleterious role in AAA using multimodality imaging. A special emphasis was put on the ability of magnetic resonance imaging (MRI) to monitor the biological activities of ILT without exogenous contrast, by evaluating its iron content. Results Increased FDG uptake was a diameter-independent marker of AAA-related events over 2 years. Missing dichotomy prevented such a fi nding for increased wall stress, although its correlation with increased FDG uptake indicates a potentially comparable value in terms of risk management. Wall metabolism is infl uenced by patient-specifi c susceptibility factors, indicating hereditary or acquired alteration of the biological responses to wall stress. The concept of risk-equivalent diameters on FES links biomechanical estimates to basic conclusions drawn from large diameter-based clinical AAA trials. Our retrospective and diameter-adjusted validation analysis verifi ed that biomechanical risk indicators are higher in ruptured than non-ruptured AAAs. Part of the FDG uptake is associated with biological activity along the luminal surface of the ILT, where we experimentally demonstrated phagocytosis of superparamagnetic iron oxide on MRI , both ex vivo and in vivo. This phagocytosis is correlated with the abundance of leukocytes and proteolytic activity. In addition, unenhanced MRI appearances resulting from the endogenous iron distribution within ILT also relate to these biological activities. Lastly, multimodality imaging was used to confi rm the concept of the deleterious role of the ILT in AAA growth in a model of AAA by infusion of elastase in the rat. Conclusion MRI and FDG PET are capable of evidencing and quantifying in vivo some of the notoriously deleterious biological processes taking place in the aneurysmal sac, especially related to the entrapped phagocytes and red blood cells in ILT and the periadventitial infl ammatory response. The central role played by ILT and its biological activities was demonstrated in vivo using several imaging techniques. The clinical value of imaging these biological activities is epitomized by a diameterindependent 2-year increased risk of event in AAA with increased wall metabolism. [less ▲]

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See detailSome misunderstood or unknown LaTeX tricks (XVI)
Merciadri, Luca ULg

E-print/Working paper (2015)

This is the second (and last) part of the tricks I found on StackExchange. First part began in the preceding issue. We will begin by a personal trick, and end by some inquiry about my LaTeX Tips & Tricks.

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See detailSome misunderstood or unknown LaTeX tricks (XV)
Merciadri, Luca ULg

E-print/Working paper (2015)

After having looked at about 150 StackExchange pages of 50 topics (that sums up to about 7500 topics’ names), I give you, in this article and in the next issue, the most interesting topics’ answers to my ... [more ▼]

After having looked at about 150 StackExchange pages of 50 topics (that sums up to about 7500 topics’ names), I give you, in this article and in the next issue, the most interesting topics’ answers to my eyes. We will first begin by two additions in regard to 31(3), 32(1). [less ▲]

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See detailZones humides : entre modifications environnementales et actions humaines
Ozer, Pierre ULg

Conference (2015, February 08)

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See detailQuand science politique et droit dialoguent : quelle typologie des instruments mémoriels en fonction du degré de contrainte ?
Grandjean, Geoffrey ULg

Conference (2015, February 07)

Envisager les études sur la mémoire comme sous-champ de la science politique francophone ouvre des pistes enrichissantes pour les politologues, notamment lorsqu’ils sont amenés à analyser les instruments ... [more ▼]

Envisager les études sur la mémoire comme sous-champ de la science politique francophone ouvre des pistes enrichissantes pour les politologues, notamment lorsqu’ils sont amenés à analyser les instruments mémoriels régissant un ou plusieurs système(s) politique(s). Dans cette perspective, la communication vise à présenter, d’un point de vue épistémologique, les apports découlant de l’interaction entre les sciences politique et juridique dans le processus de consolidation des études sur la mémoire comme sous-champ disciplinaire de la science politique. Plus précisément, la communication vise à offrir une typologie des instruments mémoriels en fonction du degré de contrainte et d’imposition d’une mémoire officielle. Par exemple, une résolution adoptée par une assemblée législative est faiblement contraignante alors qu’une loi réprimant le négationnisme impose à la fois une mémoire officielle tout en sanctionnant pénalement les citoyens qui ne la respectent pas. La typologie passe en revue les multiples instruments mémoriels pouvant être adoptés par les autorités publiques : résolution, loi déclarative, loi pénale, plan de commémorations ou encore mise en valeur d’un lieu de mémoire. L’accent est mis sur les instruments mémoriels de deux pays francophones : la Belgique et la France. Au final, cette communication permet d’insister sur l’apport de la science politique en analysant l’exercice de prérogatives de puissance publique et sur l’apport de la science juridique en classifiant les types d’instruments mémoriels en fonction du degré de contrainte ; tout en faisant dialoguer des cas d’étude différents. [less ▲]

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