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See detailWalnut husk fly, Rhagoletis completa (Diptera: Tephritidae), invades Europe: invasion potential and control strategies
Verheggen, François ULg; Verhaeghe, Agnès; Giordanengo, Philippe et al

in Applied Entomology and Zoology (2017), 52(1), 1-7

Rhagoletis completa Cresson (Diptera: Tephritidae) is native to North America and invaded Western Europe in the late 1980s, causing important damage to its principal host, walnut (Juglans spp.). In this ... [more ▼]

Rhagoletis completa Cresson (Diptera: Tephritidae) is native to North America and invaded Western Europe in the late 1980s, causing important damage to its principal host, walnut (Juglans spp.). In this review, we summarize the important elements of R. completa’s biology, phytosanitary status and methods used in Europe for its control, and then present the main conclusions associated with a completed risk analysis performed in 2014 to evaluate the dispersion and establishment potential of R. completa in Europe. The walnut husk fly was initially identified in Switzerland (1988) and Italy (1991), from where it spread to at least seven additional countries: France, Spain, Germany, Austria, Croatia, Slovenia and Hungary. R. completa has not reached the limits of its potential distribution. The main dissemination pathways within Europe include: (1) natural adult dissemination; (2) adult hitchhiker behaviour; and, to a lesser extent, (3) transportation of larvae in fresh fruits. R. completa host plants are widely distributed in Europe, either as isolated wild trees or in orchards, favouring the probability of fly establishment in currently fly-free areas. In addition, the European territories where Juglans species are present share biogeographic similarities. In orchards where R. completa is present and uncontrolled, 100% of walnut trees can be infested, causing losses in walnut yields of up to 80%. The negative effect is low (<10% yield loss) under phytosanitary control, although additional costs must also be considered to support specific monitoring for R. completa. The information presented here underlines a strong need for better walnut husk fly monitoring across European countries, as well as for increasing efforts to develop biological methods to control this emerging pest. [less ▲]

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See detailLe biologique et le social. Bergson, Durkheim et les modernes
Caeymaex, Florence ULg

in Madelrieux, S.; Stiegler, B. (Eds.) Du biologique au politique. James, Dewey, Bergson (2017)

La contribution met en évidence les implications de l'analogie biologique dans l'école sociologique française et la manière dont elle se formule dans la théorie sociale de Bergson, et dans sa conception ... [more ▼]

La contribution met en évidence les implications de l'analogie biologique dans l'école sociologique française et la manière dont elle se formule dans la théorie sociale de Bergson, et dans sa conception de la morale. La naturalisation du social, qui repose sur un usage actif des métaphores et des images biologiques chez Bergson, ouvre une réflexion originale sur la normativité sociale et la puissance transformatrice des sentiments moraux, tant sur le plan éthique que sur le plan politique. [less ▲]

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See detailRegeneration after fire in campo rupestre: Short- and long-term vegetation dynamics
Le Stradic, Soizig ULg; Hernandez, P.; Fernandes, G. W. et al

in Flora: Morphology, Distribution, Functional Ecology of Plants (2017)

The Cerrado (Brazilian savanna) is the second largest biome in Brazil, covering 22% of the country, and campo rupestre is one of the most biodiverse ecosystem. Campo rupestre are extremely old mountaintop ... [more ▼]

The Cerrado (Brazilian savanna) is the second largest biome in Brazil, covering 22% of the country, and campo rupestre is one of the most biodiverse ecosystem. Campo rupestre are extremely old mountaintop tropical ecosystems, composed of a mosaic of herbaceous, shrubland and savanna vegetation, generally located above 900. m above sea level characterized by shallow, acidic and nutrient-poor soils. In the context of increased land-use changes, effective conservation and management projects appear necessary to guarantee the conservation of these ecosystems. Although fire is a natural disturbance in campo rupestre, the effects of fire on vegetation dynamics remain poorly understood. Our objective was to assess the effects of fire on vegetation recovery and plant composition on both the short- and long-term in the main herbaceous vegetation types: the sandy and stony grasslands. We monitored plant community composition before and after a wildfire in order to assess the short-term vegetation recovery. Diachronic analyses of grasslands burnt at various dates were used to understand the effects of fire on the long-term vegetation dynamics. Our results highlighted a rapid recovery of campo rupestre vegetation after wildfires, suggesting a high adaptation to fire of plant communities. We did not find a significant variation in species richness of sandy grasslands according to time after fire, whereas higher species richness was observed in the recently burnt stony grasslands. No change in plant composition of campo rupestre in response to fire was highlighted, probably due to the high heterogeneity of this ecosystem. After fire, biomass gradually increased over time in both vegetation types. High biomass accumulation could lead to stronger fires. Further studies are necessary to understand the relationship between biomass accumulation and fire intensity in campo rupestre in order to set up adapted fire management strategies to conserve campo rupestre biodiversity. © 2017 Elsevier GmbH. [less ▲]

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See detailWidespread activity of multiple lineages of Usutu virus, western Europe, 2016.
Cadar, Daniel; Luhken, Renke; van der Jeugd, Henk et al

in Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin (2017), 22(4),

In the summer of 2016, Belgium, France, Germany and the Netherlands reported widespread Usutu virus (USUV) activity based on live and dead bird surveillance. The causative USUV strains represented four ... [more ▼]

In the summer of 2016, Belgium, France, Germany and the Netherlands reported widespread Usutu virus (USUV) activity based on live and dead bird surveillance. The causative USUV strains represented four lineages, of which two putative novel lineages were most likely recently introduced into Germany and spread to other western European countries. The spatial extent of the outbreak area corresponded with R0 values > 1. The occurrence of the outbreak, the largest USUV epizootic registered so far in Europe, allowed us to gain insight in how a recently introduced arbovirus with potential public health implications can spread and become a resident pathogen in a naive environment. Understanding the ecological and epidemiological factors that drive the emergence or re-emergence of USUV is critical to develop and implement timely surveillance strategies for adequate preventive and control measures. Public health authorities, blood transfusion services and clinicians in countries where USUV was detected should be aware of the risk of possible USUV infection in humans, including in patients with unexplained encephalitis or other neurological impairments, especially during late summer when mosquito densities peak. [less ▲]

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See detailOrganic Farming and Small-Scale Farmers: Main Opportunities and Challenges
Jouzi, Zeynab; Azadi, Hossein ULg; Taheri, Fatemeh et al

in Ecological Economics (2017), 132(February 2017), 144-154

Producing enough food to meet the needs of a growing population has always been the greatest concern of food policy-makers around the world. Given the increasing attention to organic farming (OF), we ... [more ▼]

Producing enough food to meet the needs of a growing population has always been the greatest concern of food policy-makers around the world. Given the increasing attention to organic farming (OF), we conducted this study to investigate the main opportunities and challenges of the food production system of small-scale farmers in developing countries with an emphasis on their livelihoods. The study showed that the most significant advantages of OF are environmental protection and a higher resilience to environmental changes, increasing farmers' income and reducing external input cost, enhancing social capacity and increasing employment opportunities. A s well as enhancing food security primarily by increasing the food purchasing power of local people. However, the main challenges of this food production system include lower yields in comparison to conventional systems, difficulties with soil nutrient management, certification and market barriers, and the educational and research needs of small-holders. The paper concludes that even though OF might present some significant challenges to small-scale farmers, it could/should still be considered as a part of the solution and means of improving their livelihoods. [less ▲]

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See detailProcédure pénale
Michiels, Olivier ULg

Learning material (2017)

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See detailUne architecture de frontières : les monastères des annonciades célestes dans les Trois-Evêchés (17e-18e siècles)
Piront, Julie ULg

in Bourdieu, Catherine (Ed.) Vie religieuse féminine dans les Trois-Evêchés : vocations, missions et cadres d'existence (2017)

Les Trois-Evêchés ont été un terrain fertile pour les congrégations féminines aux 16e-18e siècles puisqu'ils ont vu la naissance de projets religieux conjuguée à une installation massive de « nouveaux ... [more ▼]

Les Trois-Evêchés ont été un terrain fertile pour les congrégations féminines aux 16e-18e siècles puisqu'ils ont vu la naissance de projets religieux conjuguée à une installation massive de « nouveaux ordres » nés ou réformés dans le sillage du concile de Trente. Fondées en Italie au début du 17e siècle, les annonciades célestes se sont implantées majoritairement sur la « dorsale catholique ». Au cœur de ce territoire de frontières, les Trois-Évêchés occupent une position géographique, politique et religieuse incontournable. Dans le cadre de cette journée d’études, il s’agira d’interroger les spécificités éventuelles des cinq monastères que les annonciades célestes firent édifier dans les Trois-Évêchés en les comparant à l’ensemble de la production architecturale de l’ordre en Europe aux 17e et 18e siècles. En allant plus loin, nous verrons comment les représentations mentales de ces édifices ont participé à la genèse de l’identité de l’ordre, notamment grâce aux sources écrites et iconographiques qui en témoignent. [less ▲]

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See detailMembrane Interactions of Natural Cyclic Lipodepsipeptides of the Viscosin Group
Geudens, Niels; Nasir, Mehmet Nail ULg; Crowet, Jean-Marc ULg et al

in Biochimica et Biophysica Acta - Biomembranes (2017), 1859(3), 331-339

Many Pseudomonas spp. produce cyclic lipodepsipeptides (CLPs), which, besides their role in biological functions such as motility, biofilm formation and interspecies interactions, are antimicrobial. It ... [more ▼]

Many Pseudomonas spp. produce cyclic lipodepsipeptides (CLPs), which, besides their role in biological functions such as motility, biofilm formation and interspecies interactions, are antimicrobial. It has been established that interaction with the cellular membrane is central to the mode of action of CLPs. In this work, we focus on the CLPs of the so-called viscosin group, aiming to assess the impact of the main structural variations observed within this group on both the antimicrobial activity and the interaction with model membranes. The antimicrobial activity of viscosin, viscosinamide A, WLIP and pseudodesmin A were all tested on a broad panel of mainly Gram-positive bacteria. Their capacity to permeabilize or fuse PG/PE/cardiolipin model membrane vesicles is assessed using fluorescent probes. We find that the Glu2/Gln2 structural variation within the viscosin group is the main factor that influences both the membrane permeabilization properties and the minimum inhibitory concentration of bacterial growth, while the configuration of the Leu5 residue has no apparent effect. The CLPmembrane interactions were further evaluated using CD and FT-IR spectroscopy on model membranes consisting of PG/PE/cardiolipin or POPC with or without cholesterol. In contrast to previous studies, we observe no conformational change upon membrane insertion. The CLPs interact both with the polar heads and aliphatic tails of model membrane systems, altering bilayer fluidity, while cholesterol reduces CLP insertion depth [less ▲]

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See detailTwo new species in the Micarea prasina group from Western Europe
van den Boom, Pieter P. G.; Brand, A. Maarten; Coppins, Brian J. et al

in Lichenologist (2017), 49(1), 13-25

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See detailShip collision analysis on Offshore Wind Turbine monopile foundations
Bela, Andreea ULg; Le Sourne, Hervé; Buldgen, Loïc ULg et al

in Marine Structures (2017), 51

An offshore wind farm covers a large maritime area and the site can be located close to traffic lanes of commercial and passenger ships, which may lead to possible collision events. The work presented in ... [more ▼]

An offshore wind farm covers a large maritime area and the site can be located close to traffic lanes of commercial and passenger ships, which may lead to possible collision events. The work presented in this paper aimed to understand both the crushing behavior and the nacelle dynamics of a predefined monopile offshore wind turbine when impacted by a ship. Another objective was to deeply investigate the influence of various parameters like ship impact velocity and location, wind direction, soil stiffness and deformability of the striking ship. First, nonlinear numerical simulations of ship - Offshore Wind Turbine (OWT) collisions have been carried out with a rigid striking ship for a better understanding of the OWT’s structural behaviour during collision. Different configurations for the wind turbine’s structure have been used in order to highlight the modifications in behaviour induced by changing the soil conditions or the loading scenario. The resulting resistant force and internal energies have been compared as well as the tower top (nacelle) displacements and accelerations. Then, another series of simulations have been performed with a deformable ship in order to investigate the influence of the deformability of the striking ship on the OWT’s behaviour. It is worth noting that all these numerical results will further serve to fix the hypotheses for the development of a simplified tool based on analytical formulations. [less ▲]

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See detailCXCL12 mediates glioblastoma resistance to radiotherapy in the subventricular zone.
Goffart, Nicolas ULg; Lombard, Arnaud; Lallemand, François ULg et al

in Neuro-Oncology (2017), 19(1), 66-77

BACKGROUND: Patients with glioblastoma (GBM) have an overall median survival of 15 months despite multimodal therapy. These catastrophic survival rates are to be correlated to systematic relapses that ... [more ▼]

BACKGROUND: Patients with glioblastoma (GBM) have an overall median survival of 15 months despite multimodal therapy. These catastrophic survival rates are to be correlated to systematic relapses that might arise from remaining glioblastoma stem cells (GSCs) left behind after surgery. In this line, it has recently been demonstrated that GSCs are able to escape the tumor mass and preferentially colonize the adult subventricular zone (SVZ). At a distance from the initial tumor site, these GSCs might therefore represent a high-quality model of clinical resilience to therapy and cancer relapses as they specifically retain tumor-initiating abilities. METHOD: While relying on recent findings that have validated the existence of GSCs in the human SVZ, we questioned the role of the SVZ niche as a potential GSC reservoir involved in therapeutic failure. RESULTS: Our results demonstrate that (i) GSCs located in the SVZ are specifically resistant to radiation in vivo, (ii) these cells display enhanced mesenchymal roots that are known to be associated with cancer radioresistance, (iii) these mesenchymal traits are specifically upregulated by CXCL12 (stromal cell-derived factor-1) both in vitro and in the SVZ environment, (iv) the amount of SVZ-released CXCL12 mediates GBM resistance to radiation in vitro, and (v) interferes with the CXCL12/CXCR4 signalling system, allowing weakening of the tumor mesenchymal roots and radiosensitizing SVZ-nested GBM cells. CONCLUSION: Together, these data provide evidence on how the adult SVZ environment, through the release of CXCL12, supports GBM therapeutic failure and potential tumor relapse. [less ▲]

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See detailLe choix du liégeois. Dîmègne de Louis Remacle
Baiwir, Esther ULg; Biquet, Stéphanie ULg

in Baiwir, Esther; Biquet, Stéphanie (Eds.) Petite anthologie subjective de littérature wallonne (2017)

Lecture et commentaire du seul poème en liégeois de Louis Remacle, "Dîmègne".

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See detailSampling only ten microliters of whole blood for the quantification of poorly soluble drugs: Itraconazole as case study
Thiry, Justine ULg; Evrard, Brigitte ULg; Nys, Gwenaël ULg et al

in Journal of Chromatography. A (2017), 1479

Nowadays in animal studies, it is important to comply with the so-called Three Rs rule by replacing or reducing the number of tested animals. Volumetric absorptive microsampling (VAMS) can be used to ... [more ▼]

Nowadays in animal studies, it is important to comply with the so-called Three Rs rule by replacing or reducing the number of tested animals. Volumetric absorptive microsampling (VAMS) can be used to collect small quantities (10 or 20 µL) of whole blood, thereby limiting the amount of animals needed. In this study, a quantitative method was developed and subsequently validated for the poorly soluble drug itraconazole (ITZ) using VAMS and ultra-high performance liquid chromatography (UHPLC) coupled to tandem mass spectrometry (MS). A proof of concept study showed that the optimized method is applicable to test the bioavailability of drug formulations containing ITZ. Using VAMS, smaller blood volumes can be taken per sampling point (10-20 µL instead of the conventional 0.2-0.5 mL) avoiding the sacrifice of animals. Moreover, the same rats can be used to compare different drug formulations which strengthens the validity of the results. In long-term bioavailability studies, it is necessary to guarantee the stability of the tested drugs supported on VAMS devices. In this study, we show that ITZ was only stable for 24 hours after collection with VAMS, but for at least two weeks by the storage of extracted samples at -80°C. [less ▲]

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See detailInteractive effects of ultraviolet radiation and thermal stress on two reef-building corals
Courtial, Lucile; Roberty, Stéphane ULg; Shick, Malcom et al

in Limnology and Oceanography (2017)

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See detailMolecular dynamics study of micelle proeprties according to their size
Lebecque, Simon ULg; Crowet, Jean-Marc ULg; Nasir, Mehmet Nail ULg et al

in Journal of Molecular Graphics and Modelling (2017)

Surfactants are molecules able to spontaneously self-assemble to form aggregates with well-defined properties, such as spherical micelles, planar bilayers, cylindrical micelles or vesicles. Micelles have ... [more ▼]

Surfactants are molecules able to spontaneously self-assemble to form aggregates with well-defined properties, such as spherical micelles, planar bilayers, cylindrical micelles or vesicles. Micelles have notably several applications in many domains, such as drug delivery or membrane protein solubilization. In this context, the study of micelle formation in relation with the structural and physico-chemical properties of surfactants is of great interest to better control their use in the different application fields. In this work, we use the MD approach developed by Yoshii et al. and extend it to surfactants with different structures. We aim to systematically investigate different micellar properties as a function of the aggregates size by a molecular dynamics approach, to get an insight into the micellar organization and to collect some relevant descriptors about micelle formation. For this, we perform short MD simulations of preformed micelles of various sizes and analyze three parameters for each micelle size, namely the eccentricity of the micelles, the hydrophobic/hydrophilic surface ratio and the hydrophobic tails hydration. If these parameters are known descriptors of micelles, they were not yet studied in this way by MD. We show that eccentricity, used as “validator” parameter, exhibits minimal values when the aggregate size is close to the experimental aggregation number for surfactants that are known to form spherical micelles. This hence indicates that our methodology gives consistent results. The evolution of the two descriptors follows another scheme, with a sharp increase and decrease, respectively, followed by a leveling-off. The aggregate sizes at which this stabilization starts to occur are close to the respective aggregation number of each surfactant. In our approach, we validate the use of these descriptors to follow micelle formation by MD, from “simple” surfactants to more complex structures, like lipopeptides. Our calculations also suggest that some peculiar behavior, like that of TPC, can be highlighted by our approach. In the context of peptidic surfactants, our methodology could further help to improve computer simulations combined to molecular thermodynamic models to predict micellar properties of those more complex amphiphilic molecules. [less ▲]

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See detailAssessing inter- and intramolecular continuous-flow strategies towards methylphenidate (Ritalin) hydrochloride
Gerardy, Romaric ULg; Winter, Marc; Vizza, Alessandra et al

in Reaction Chemistry and Engineering (2017)

The batch-to-flow translation of inter- and intramolecular strategies for the diastereoselective preparation of the active pharmaceutical ingredient threo-methylphenidate hydrochloride is presented. Both ... [more ▼]

The batch-to-flow translation of inter- and intramolecular strategies for the diastereoselective preparation of the active pharmaceutical ingredient threo-methylphenidate hydrochloride is presented. Both inter- and intramolecular strategies imply the telescoping of multiple processing steps and the generation of unstable diazo species under continuous-flow conditions. The intermolecular strategy relies on an unprecedented continuous-flow Rh-catalyzed intermolecular C–H carbene insertion, providing enriched threo-N-Boc methylphenidate in 38% or 19% isolated yield according to sequential or fully telescoped processes, respectively. Quantitative Boc-deprotection is carried out off-line. The intramolecular strategy relies on a continuous-flow thermal intramolecular C–H carbene insertion, providing enriched threo-methylphenidate hydrochloride in 70% isolated yield. A continuous-flow photochemical alternative is also presented. The critical step of the most promising intramolecular strategy is implemented on the mesoscale in a pilot-scale continuous-flow reactor. [less ▲]

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See detailStudy Protocol: Effect of prenatal wheel-running exercise (before and during gestation) on cocaine psychomotor sensitization expressed in the offspring in periadolescent females and males C57BL/6J mice
Lespine, Louis-Ferdinand ULg; Plenevaux, Alain ULg; Tirelli, Ezio ULg

E-print/Working paper (2017)

The present study principally aims at determining to which extent prenatal exercise (before and during gestation) could affect the initiation (establishment) and the expression of psychomotor ... [more ▼]

The present study principally aims at determining to which extent prenatal exercise (before and during gestation) could affect the initiation (establishment) and the expression of psychomotor sensitization induced by a representative dose of cocaine in young female and male mice. More specifically, we will assess cocaine-induced acute psychomotor-activating effects, psychomotor sensitization developing over 9 daily sessions (daily peritoneal injections of cocaine or saline) and the long-term expression of the sensitized response (30 days after the last sensitizing injection) in C57BL/6J mice born from mothers housed with or without a running wheel before and during gestation. Based on literature and on our prior results, the mice born from exercised mothers are expected to show significantly reduced levels of cocaine responsiveness in comparison with the control mice (born from unexercised mothers). [less ▲]

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See detailSystématiser les associations. Le concept hjelmslévien de paradigme et son héritage greimassien
Badir, Sémir ULg; Cigana, Lorenzo ULg

in Signata. Annales des Sémiotiques = Annals of Semiotics (2017), 8

This paper aims to explore the notion of “paradigm” by following its development in the epistemology of linguistics and semiotics of the twentieth century through three landmarks: its first use within ... [more ▼]

This paper aims to explore the notion of “paradigm” by following its development in the epistemology of linguistics and semiotics of the twentieth century through three landmarks: its first use within linguistics, by Ferdinand de Saussure, its redefinition by Louis Hjelmslev, and its reinterpretation in textual semiotics by Algirdas J. Greimas. The concept of “paradigm” represents, more than others, the very target of structuralist theorisation. Marking the transition between openness and closeness of linguistic categories, it crystallises the structuralist ambition to bring the dynamic variability and richness of semiotic phenomena back to a closed, or at least stable, inventory of functional ground elements. [less ▲]

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See detailPitfalls in supermatrix phylogenomics
Philippe, Hervé; Vienne, Damien M. De; Ranwez, Vincent et al

in European Journal of Taxonomy (2017), 283

In the mid-2000s, molecular phylogenetics turned into phylogenomics, a development that improved the resolution of phylogenetic trees through a dramatic reduction in stochastic error. While some then ... [more ▼]

In the mid-2000s, molecular phylogenetics turned into phylogenomics, a development that improved the resolution of phylogenetic trees through a dramatic reduction in stochastic error. While some then predicted “the end of incongruence”, it soon appeared that analysing large amounts of sequence data without an adequate model of sequence evolution amplifies systematic error and leads to phylogenetic artefacts. With the increasing flood of (sometimes low-quality) genomic data resulting from the rise of high-throughput sequencing, a new type of error has emerged. Termed here “data errors”, it lumps together several kinds of issues affecting the construction of phylogenomic supermatrices (e.g., sequencing and annotation errors, contaminant sequences). While easy to deal with at a single-gene scale, such errors become very difficult to avoid at the genomic scale, both because hand curating thousands of sequences is prohibitively time-consuming and because the suitable automated bioinformatics tools are still in their infancy. In this paper, we first review the pitfalls affecting the construction of supermatrices and the strategies to limit their adverse effects on phylogenomic inference. Then, after discussing the relative non-issue of missing data in supermatrices, we briefly present the approaches commonly used to reduce systematic error. [less ▲]

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See detailRobust asymptotic tests for the equality of multivariate coefficients of variation
Aerts, Stéphanie ULg; Haesbroeck, Gentiane ULg

in TEST (2017), 26(1), 163-187

In order to easily compare several populations on the basis of more than one feature, multivariate coefficients of variation (MCV) may be used as they allow to summarize relative dispersion in a single ... [more ▼]

In order to easily compare several populations on the basis of more than one feature, multivariate coefficients of variation (MCV) may be used as they allow to summarize relative dispersion in a single index. However, up to date, no test of equality of one or more MCV's has been developed in the literature. In this paper, several classical and robust Wald type tests are proposed and studied. The asymptotic distributions of the test statistics are derived under elliptical symmetry, and the asymptotic efficiency of the robust versions is compared to the classical tests. Robustness of the proposed procedures is examined through partial influence functions of the test statistic, as well as by means of power and level influence functions. A simulation study compares the performance of the classical and robust tests under uncontaminated and contaminated schemes, and the difference with the usual covariance homogeneity test is highlighted. As a by-product, these tests may also be considered in the univariate context where they yield procedures that are both robust and easy-to-use. They provide an interesting alternative to the numerous parametric tests of comparison of univariate coefficients of variation existing in the literature, which are, in most cases, unreliable in presence of outliers. The methods are illustrated on a real data set. [less ▲]

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