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See detailDevelopment of a translation stage for in situ non-invasive analysis and high resolution imaging
Strivay, David ULg; Clar, Mathieu ULg; Rakkaa, Saïd ULg et al

Poster (2016, March)

Non-invasive imaging techniques and analytical instrumentation for cultural heritage object studies have undergone a tremendous development over the last years. Many new miniature and/or handheld systems ... [more ▼]

Non-invasive imaging techniques and analytical instrumentation for cultural heritage object studies have undergone a tremendous development over the last years. Many new miniature and/or handheld systems have been developed and optimized. Nonetheless, these instruments are usually used with a tripod or a manual position system. This is very time consuming when performing point analysis or 2D scanning of a surface. The Centre Européen d’Archéométrie (CEA) has build a translation system made of pluggable rails of 1 m long with a maximum length and height of 3 m. Three motors embedded in the system allow the platform to be moved along these axis, toward and backward from the sample. The rails hold a displacement system, providing a continuous movement. Any position can be reached with a reproducibility of 0.1 mm. The displacements are controlled by an Ethernet connection through a laptop computer running a multiplatform homemade software written in JAVA. This software allows a complete control over the positioning using a simple, unique, and concise interface. Automatic scanning can be performed over a large surface of 3 meters on 3 meters. The Ethernet wires provide also the power for the different motors and, if necessary the detection head. The platform has been originally designed for a XRF detection head (with its full power alimentation) but now can accommodate many different systems like IR reflectography, digital camera, hyperspectral camera, Raman probes, etc. The positioning system can be modified to combine the acquisition software of the imaging or analytical techniques and the positioning software. [less ▲]

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See detail“Color is a kind of holy substance for me”: analytical study of the Sam Francis’ palette from the 1940’s to the 1990’s
Defeyt, Catherine ULg; Mazurek, Joy; Zebala, Aneta et al

Poster (2016, March)

The Sam Francis’s colors, literally described as vivid, saturated, pure, vibrant intense and rich, largely contribute to the unique character of his work. This idiosyncrasy explains the interest in ... [more ▼]

The Sam Francis’s colors, literally described as vivid, saturated, pure, vibrant intense and rich, largely contribute to the unique character of his work. This idiosyncrasy explains the interest in conducting an extended study on the Francis’ painting materials through analytical techniques. On the other hand, many Francis’ paintings display colored surfaces that exhibit bronzing, fluorescent or opalescent effects. As a consequence, retouching paint losses from Sam Francis works may become a challenging task for the involved conservators, the degree of the color matching required in the imitative technique being particularly difficult to attain, in the presence of such surfaces. Furthermore, the attained degree of the color match has to be conserved in all conditions of illumination and observation. The use of pigments chemically similar to the original ones is often necessary for matching highly chromatic pigments. Though, many modern synthetic organic pigments (SOPs) possess high color strength. That is why the characterization of the Francis palette would provide helpful information to the conservators, which have to deal with this type of issue. The upcoming Getty publication Sam Francis: The Artist’s Materials, planned for 2016, offered the opportunity for in-depth analyses of hundreds paint samples. Almost three hundreds of paint fragments supplied by the Sam Francis Foundation have been investigated at the GCI laboratory, by using three complementary analytical techniques, Py-GC-MS, Raman and FTIR spectroscopies. The Raman spectroscopy is one of the most efficient techniques for identifying SOPs in paint systems, while the Py-GC-MS and FTIR methods provide essential information concerning the binding media. The analyzed paint fragments were sampled from twenty-nine canvases and works on paper, made between 1946 and 1992. Although, primary established in Southern California, Sam Francis spent numerous long journeys in different places around the world, including Paris, Bern, Mexico City, New York and Tokyo. However, the material study has outlined the uninterrupted use of` certain classes of SOPs in specific colors. For example, copper phthalocyanine (CuPc) pigments were systematically detected in the blue and green samples, while azo pigments have been identified in most of the yellow areas sampled from post 1940s works. Regardless of the support and the paint technique, the Francis’ blues primary contain Ultramarine and/or CuPc blue pigments. And, it has been shown that the bronzing blue surfaces noticed for some of the investigated artworks correspond to PB15-based paint films. The present study has also underlined the recurrent use of perinone orange and dioxazine violet in fluorescent orange and purple area. Despite the early introduction of SOPs, on the Francis’ palette, the works dating from the 1940’s remained mainly composed of traditional inorganic pigments, for instance lead white and red, chrome yellow, viridian and iron oxides. Interestingly, various binding media, i.e. Shellac gum, modified and unmodified oils, PVA, alkyd resins and acrylic copolymers have been identified. Actually, the investigated samples have pointed out the frequent combination of more than three types of binders on a same painting. Through the identification of the various SOPs used by Francis over fifty years, this research provide helpful information for selecting the most appropriate retouching pigments. [less ▲]

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See detailSURVEYS OF APHIDS AND POTATO VIRUS Y IN POTATO FIELDS IN WALLONIA, BELGIUM: A FOUR YEAR OVERVIEW
Bosquée, Emilie ULg; Yattara, Almouner A.; Crutzen, François et al

in Journal of Plant Pathology [=JPP] (2016)

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified ... [more ▼]

Populations of Potato virus Y (PVY) and aphids were characterized in potato seed and stock production fields in southern Belgium (Wallonia) from 2009 to 2012. More than 40 aphid species were identified using yellow pan traps. Four thousands potato leaf samples collected in 87 plots from 29 fields were analysed for the presence and typing of PVY strains by RT-PCR. PVY was detected in 26%, 20% and 60% of the seed plots tested from 2009 to 2011, respectively. A higher prevalence of PVY was observed in plots of stock potatoes (60% in 2010 and 67% in 2011). The N/NTN strain of PVY was predominant, representing 70-99% of the strains. [less ▲]

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See detailL’entretien de tutorat documenté : un accompagnement réflexif ?
Alonso Vilches, Vincent ULg; Pirard, Florence ULg

in Education Permanente (2016), 206(1), 131-138

Notre contribution interroge l’activité tutorale dans un métier adressé à autrui, celui des professionnels de l’enfance. Elle souligne la complexité d’une telle activité dans un travail fondé sur des ... [more ▼]

Notre contribution interroge l’activité tutorale dans un métier adressé à autrui, celui des professionnels de l’enfance. Elle souligne la complexité d’une telle activité dans un travail fondé sur des référents multiples, qui nécessitent le développement d’une réflexivité sensible à la singularité des situations quotidiennes. Elle propose une analyse de moments d’entretien de tutorat accompagnés par un professionnel sur base d’une documentation vidéo. Elle montre que ces moments ne permettent pas forcément au stagiaire de développer une représentation signifiante de la situation ni d’en dégager les inférences nécessaires pour ajuster son action. [less ▲]

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See detailNote on the numerical solution of the scalar Helmholtz equation in a nanotorus with uniform Dirichlet boundary conditions
Nguyen, Ngoc Duy ULg; Evrard, Roger ULg; Stroscio, Michael

E-print/Working paper (2016)

This note describes the solution of the Helmholtz equation inside a nanotorus with uniform Dirichlet boundary conditions. The eigenfunction symmetry is discussed and the lower-order eigenvalues and ... [more ▼]

This note describes the solution of the Helmholtz equation inside a nanotorus with uniform Dirichlet boundary conditions. The eigenfunction symmetry is discussed and the lower-order eigenvalues and eigenfunctions are shown. The similarity with the case of a long cylinder and with that of the vibrations of a circular elastic membrane is discussed. This similarity is used to propose a classification scheme of the eigenfunctions based on three indices. [less ▲]

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See detailA One-year Survey of Microsporum audouinii infections in Belgium: epidemiological and genotypic characterisation
SACHELI, Rosalie ULg; ADJETEY BAHUN, Akolé ULg; DARFOUF, Rajae ULg et al

in Clinical Microbiology and Infection (2016), 22(3), 2859-28517

During recent years the proportion of tinea capitis (TC) infections due to Microsporum audouinii (M. audouinii) has increased both in Belgium and other European countries. To better understand the ... [more ▼]

During recent years the proportion of tinea capitis (TC) infections due to Microsporum audouinii (M. audouinii) has increased both in Belgium and other European countries. To better understand the emergence of this species in the country, the Belgian National Reference Center (NRC) for dermatophytes launched an epidemiological survey on the main anthropophilic dermatophytes causing TC in Belgium and including the genomic characterization of M. audouinii isolates. In total, 116 strains of M. audouinii were confirmed and characterized by the DiversiLab® system (bioMérieux). Six genotypic variants were identified, among which one major group included 90 isolates and the reference strain. Another variant group (11 strains) was exclusively confined to a geographical region in South Belgium. Analysis of epidemiological characteristics of the infected population showed that the main age category concerned 5-9 year-old children with a sex ratio (Male/Female) of 1.97. Data concerning the geographic origin of the family revealed a majority of Belgian nationality (44.7%), suggesting that the contamination has originated in Belgium. Other nationalities primarily originated from Africa. At this time, no clear correlation has been established between one particular strain and a specific country of origin. [less ▲]

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See detailAntihyperglycémiants, antihypertenseurs et hypolipidémiants : comparaison des effets sur la mortalité et la morbidité cardiovasculaire chez le patient diabétique de type 2
SCHEEN, André ULg

Poster (2016, March)

Introduction : Réduire le risque de mortalité et morbidité cardiovasculaire (CV) chez le patient diabétique de type 2 (DT2) est primordial, mais les effets protecteurs semblent différents selon le mode ... [more ▼]

Introduction : Réduire le risque de mortalité et morbidité cardiovasculaire (CV) chez le patient diabétique de type 2 (DT2) est primordial, mais les effets protecteurs semblent différents selon le mode d’intervention pharmacologique étudié. Patients et méthodes : Les données de mortalité (totale et CV) et morbidité (infarctus du myocarde ou IDM, accidents vasculaires cérébraux ou AVC) rapportées (réduction du risque relatif) dans les essais ayant testé un traitement anti-hyperglycémiant sont comparées avec les résultats publiés dans deux méta-analyses concernant les hypolipidémiants et les anti-hypertenseurs consacrées au DT2. Résultats : Les antihypertenseurs réduisent les IDM (-12%) et la mortalité globale (-13%) de façon comparable, et diminuent davantage les AVC (-27%). Les hypolipidémiants diminuent davantage les IDM (- 22%) et les AVC (-21%) que la mortalité globale (-9%) (ou la mortalité CV : - 13%). Les données concernant les antihyperglycémiants diffèrent considérablement selon les médications testées. L’insuline et les sulfamides (UKPDS) réduisent plus les IDM (- 21%) que la mortalité totale (-8%), mais augmentent les AVC (+ 14%). La metformine (UKPDS) réduit, de façon comparable, les IDM (-39%), les AVC (-41%) et la mortalité totale (-36%). La pioglitazone (PROactive) diminue davantage les IDM (-17%) et les AVC (-19%) que la mortalité (-4%). Les gliptines (combinaison de SAVOR TIMI 53, EXAMINE, TECOS) ont montré des effets globalement neutres sur la mortalité totale (0%), les IDM (-2%) et les AVC (-1%). L’empagliflozine (EMPA-REG OUTCOME) se singularise par un effet favorable nettement plus marqué sur la mortalité totale (-32 %) et CV (- 38%) que sur les IDM (-13%) ou les AVC (+18%). Conclusion : Les discordances observées suggèrent l’implication de mécanismes protecteurs différents selon les interventions testées. EMPA-REG OUTCOME, le seul essai démontrant un effet plus marqué sur la mortalité que sur les événements CV, suggère un mécanisme propre de l’inhibiteur des SGLT2. [less ▲]

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See detailRelations entre neuropathie autonome cardiaque (NAC), pression pulsée (PP) et insuffisance rénale chronique (IRC) chez le patient diabétique de type 2 (DT2)
PHILIPS, Jean-Christophe ULg; MARCHAND, Monique ULg; SCHEEN, André ULg

Poster (2016, March)

Objectifs : Ce travail étudie les relations entre trois complications diabétiques, la NAC, l’élévation de PP (marqueur de rigidité artérielle) et la diminution du débit de filtration glomérulaire (DFG ... [more ▼]

Objectifs : Ce travail étudie les relations entre trois complications diabétiques, la NAC, l’élévation de PP (marqueur de rigidité artérielle) et la diminution du débit de filtration glomérulaire (DFG) chez le patient DT2. Patients et méthodes : L’étude comprend 79 patients DT2 (53H/26F; 56±8 années; 11±8 années de DT2; IMC 28,4±4,6 kg/m²) analysés par enregistrement continu de la pression artérielle (PA) et de la fréquence cardiaque (appareil Finapres) lors d’un test postural standardisé. Le gain baro-réflexe (GBR, indice de NAC) correspond à la pente de la relation entre les espaces R-R et PA systolique (PAS) lors du redressement accroupi-debout. PP est analysée pendant tout le test et par son augmentation durant l’accroupissement (delta PP). DFG est estimé par la formule MDRD au début puis après un suivi moyen de 12±5 ans. Résultats : Les valeurs initiales sont : HbA1c : 8,8± 1,7%; DFG : 86±25 ml/min ; PP : 62±10 mmHg; BRG : 1,8±1,4 msec/mmHg. DFG est inversement corrélé à l’âge (r=-0,317; p=0,020), très positivement corrélé avec GBR (r=0,453; p=0,008), sans corrélation significative avec HbA1c (r=-0,023; p=0,935) ni avec PAS, PP ou encore delta PP (r=-0,206; p=0,114; NS). La diminution de DFG (-12±23 ml/min) lors du suivi de 12 ans n’a pu être corrélée de façon significative aux valeurs initiales et finales d’HbA1c, ni aux valeurs initiales de GBR (et d’autres marqueurs de NAC) ou de PA, même si la relation est proche de la signification pour delta PP (r=0,20; p=0,060). Conclusion : La forte relation initiale entre DFG et GBR suggère que IRC et NAC sont aggravées de façon conjointe et, possiblement, qu’une des deux complications influence l’autre. L’absence de toute corrélation entre la chute ultérieure de DFG et les autres paramètres initiaux peut s’expliquer par l’origine multifactorielle de la progression de l’IRC chez le patient DT2. [less ▲]

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See detailMobiliser la culture du pays d’origine, un défi pour l’intégration des migrants?
Mescoli, Elsa ULg; Gsir, Sonia ULg

Conference (2016, March)

La culture constitue pour les migrants et leurs pays d’origine un moyen de maintenir des liens réciproques après la migration. Mais quels sont les enjeux de la mobilisation de la culture d’origine pour ... [more ▼]

La culture constitue pour les migrants et leurs pays d’origine un moyen de maintenir des liens réciproques après la migration. Mais quels sont les enjeux de la mobilisation de la culture d’origine pour l’intégration des migrants dans leurs nouveaux pays de résidence ? Cette présentation analyse le déploiement de la culture du pays d’origine à trois niveaux : celui des pratiques quotidiennes des migrants, des politiques d’intégration et de diaspora et enfin, le niveau des associations, en particulier les centres culturels établis en Europe par les pays d’origine des migrants. Les pratiques culturelles des migrants et les actions et institutions culturelles mises en place par les pays d’origine sont confrontées au cadre légal européen en matière de diversité culturelle mais aussi aux politiques et discours sur l’intégration des migrants. La perspective à la fois anthropologique et sociologique adoptée révèle les processus de domination culturelle qui sont à l’œuvre. Elle permet aussi de questionner l’idée d’identité culturelle en montrant le dynamisme qui caractérise les cultures mais aussi la créativité des communautés locales dans un environnement globalisé. Finalement, on constate qu’une variété de facteurs est en jeu dans les processus d’intégration des migrants, que les dynamiques de la culture elle-même déterminent des appartenances multiples et aussi que les identités se développent au sein des interactions entre cultures. Si on ne peut établir de lien causal et univoque entre les pratiques culturelles liées au pays d’origine et l’intégration des migrants dans le pays de résidence, on peut par contre se référer à la notion d’ethnicité et à sa fonction politique (Comaroff et Comaroff, 2009). [less ▲]

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See detailToxicity of organometal halide perovskite solar cells
Babayigit, Aslihan; Ethirajan, Anitha; Muller, Marc ULg et al

in Nature Materials (2016), 15

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See detailDrying induced shrinkage of Boom Clay: an experimental investigation
Prime, Noémie; Levasseur, Séverine; Miny, Laurent et al

in Canadian Geotechnical Journal (2016), 53(3), 396-409

Drying induced shrinkage of geomaterials may have a strong effect on geostructure stability and deformation. Settlement of foundations, fracture opening on slopes, roads, tunnel walls may be due to drying ... [more ▼]

Drying induced shrinkage of geomaterials may have a strong effect on geostructure stability and deformation. Settlement of foundations, fracture opening on slopes, roads, tunnel walls may be due to drying shrinkage. However, there is still a lack of knowledge concerning shrinkage evolution in time and shrinkage propagation within the material. In this study, the shrinkage of a specific clayey rock, Boom Clay, under drying conditions is experimentally investigated. This rock is a deep geological formation which is under study for high-level and long-life radioactive waste storage in Belgium. Two experimental campaigns are here presented. The first one, based on vapour equilibrium drying technique and completed by sample size manual measurement, aims to characterize the material shrinkage in balanced states. The second one, based on convective drying technique completed by shape monitoring using X-ray tomography, aims to analyse how shrinkage develops before reaching a steady state. Both approaches put in evidence the shrinkage anisotropy of this structurally bedded rock, with a ratio around 2 between the direction of maximum strains and the direction of minimum strains. However, the two drying techniques also provide complementary results, as the relation between the amount of shrinkage and the retention curve (for the uniform drying imposed with saline solutions) and the kinetics of shrinkage propagation inside the material (for the non-uniform drying imposed with air convection). [less ▲]

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See detailStructural identifiability analysis of a cardiovascular system model
Pironet, Antoine ULg; Dauby, Pierre ULg; Chase, J. Geoffrey et al

in Medical engineering & physics (2016)

The six-chamber cardiovascular system model of Burkhoff and Tyberg has been used in several theoretical and experimental studies. However, this cardiovascular system model (and others derived from it) are ... [more ▼]

The six-chamber cardiovascular system model of Burkhoff and Tyberg has been used in several theoretical and experimental studies. However, this cardiovascular system model (and others derived from it) are not identifiable from any output set. In this work, two such cases of structural non-identifiability are first presented. These cases occur when the model output set only contains a single type of information (pressure or volume). A specific output set is thus chosen, mixing pressure and volume information and containing only a limited number of clinically available measurements. Then, by manipulating the model equations involving these outputs, it is demonstrated that the six-chamber cardiovascular system model is structurally globally identifiable. A further simplification is made, assuming known cardiac valve resistances. Because of the poor practical identifiability of these four parameters, this assumption is usual. Under this hypothesis, the six-chamber cardiovascular system model is structurally identifiable from an even smaller dataset. As a consequence, parameter values computed from limited but well-chosen datasets are theoretically unique. This means that the parameter identification procedure can safely be performed on the model from such a well-chosen dataset. Thus, the model may be considered suitable for use in diagnosis. [less ▲]

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See detailSeasonal variability of surface and column carbon monoxide over megacity Paris, high altitude Jungfraujoch and Southern Hemispheric Wollongong stations
Té, Y; Jeseck, P; Franco, Bruno ULg et al

in Atmospheric Chemistry & Physics Discussions (2016)

Carbon monoxide (CO) is an atmospheric key species due to its toxicity and its impact on the atmospheric oxidizing capacity, both factors affecting air quality. The paper studies the altitude dependent ... [more ▼]

Carbon monoxide (CO) is an atmospheric key species due to its toxicity and its impact on the atmospheric oxidizing capacity, both factors affecting air quality. The paper studies the altitude dependent seasonal variability of CO at the three different sites Paris, Jungfraujoch and Wollongong, with an emphasis on establishing a link between the CO vertical distribution and the nature of CO emission sources. The CO seasonal variability obtained from the total columns and from the free tropospheric partial columns shows a maximum around March-April and a minimum around September-October in the Northern Hemisphere (Paris and Jungfraujoch). In the Southern Hemisphere (Wollongong) this seasonal variability is shifted by about 6 months. Satellite observations by IASI-MetOp and MOPITT instruments confirm this seasonality. Ground-based FTIR is demonstrated to provide useful complementary information due to good sensitivity in the boundary layer. In situ surface measurements of CO volume mixing ratios in Paris and at Jungfraujoch reveal a time-lag of the near surface seasonal variability of about 2 months with respect to the total column variability at the same sites. The chemical transport model GEOS-Chem is employed to interpret our observations. GEOS-Chem sensitivity runs allow identifying the emission sources influencing the seasonal cycle of CO. In Paris and on top of Jungfraujoch, the surface seasonality is mainly driven by anthropogenic emissions, while the total column seasonality is also controlled by air masses transported from distant sources. In the case of Wollongong, where the CO seasonality is mainly affected by biomass burning, no time shift is observed between surface and above the boundary layer. [less ▲]

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See detailAnalyse qualitative interdisciplinaire du discours de travailleurs à l’aide d’un logiciel collaboratif : le cas de la flexicurité
Beuker, Laura ULg; DE CIA, Julie ULg; Dervaux, Amélie ULg et al

in Recherches Qualitatives (2016), 35(1), 29-55

L’ambition de cet article est double : explorer les vertus de l’utilisation d’un logiciel d’analyse qualitative dans le cadre d’un travail interdisciplinaire sur la flexicurité, et réaliser une revue de ... [more ▼]

L’ambition de cet article est double : explorer les vertus de l’utilisation d’un logiciel d’analyse qualitative dans le cadre d’un travail interdisciplinaire sur la flexicurité, et réaliser une revue de littérature transversale à partir des problématiques concrètes que ce concept cristallise dans le vécu des travailleurs. La flexicurité constitue un oxymore qui prône la recherche d’un équilibre entre besoins de flexibilité et de sécurité sur le marché du travail. Cet équilibre est avant tout un objectif politique, mais il reste fragile aux yeux des acteurs concernés. En cherchant à croiser le regard analytique de trois disciplines – psychologie, gestion et sociologie –, nous avons recouru au logiciel Cassandre (Lejeune, 2008) pour dégager des tensions discursives autour des notions de flexibilité et de sécurité dans un corpus de vingt entretiens qualitatifs. L’article permet ainsi de concrétiser l’intérêt et les limites de l’utilisation d’un logiciel d’analyse qualitative dans le cadre d’un travail interdisciplinaire. [less ▲]

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See detailTénotomie chez le veau
Djebala, Salem ULg; Sartelet, Arnaud ULg

in Point Vétérinaire (2016), 363

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See detailDisorders of Consciousness
Bodart, Olivier ULg; Thibaut, Aurore ULg; Laureys, Steven ULg et al

in Citerio, G.; Smith, M.; Kofke, A. (Eds.) Oxford Textbook of neurocritical care (2016)

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See detailReview of: K. Mulligan, Wittgenstein et la philosophie austro-allemande (Paris, 2012)
Seron, Denis ULg

in Dialectica : International Journal of Philosophy & Official Organ of the ESAP (2016), 70(1),

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See detailBad News in Service Encounters: Ideas and Insights
Delcourt, Cécile ULg; Gremler, Dwayne

Conference (2016, March)

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