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See detailLes traditions manuscrites de la Chanson de la Croisade albigeoise et de ses remaniements en prose : quelle lecture pour quelle réécriture ? 
Raguin, Marjolaine ULg

in De Riquer, Isabel; Billy, Dominique; Palumbo, Giovanni (Eds.) Actes du XXVIIe Congrès international de linguistique et de philologie romanes (Nancy, 15-20 juillet 2013). Section 14 : Littératures médiévales. Nancy, ATILF : http://www.atilf.fr/cilpr2013/actes/section-14.html. (2017)

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See detailOutcomes of UCB transplantation are comparable in FLT3+ AML: Results of CIBMTR, eurocord and EBMT collaborative analysis.
Ustun, C.; Giannotti, F.; Zhang, M.-J. et al

in Leukemia : Official Journal of the Leukemia Society of America, Leukemia Research Fund, U.K (2017)

Allogeneic hematopoietic cell transplantation (HCT) from siblings or unrelated donors (URD) during complete remission (CR) may improve leukemia-free survival (LFS) in FLT3+ acute myeloid leukemia (AML ... [more ▼]

Allogeneic hematopoietic cell transplantation (HCT) from siblings or unrelated donors (URD) during complete remission (CR) may improve leukemia-free survival (LFS) in FLT3+ acute myeloid leukemia (AML) that has poor prognosis due to high relapse rates. Umbilical cord blood (UCB) HCT outcomes are largely unknown in this population. We found that compared with sibling HCT, relapse risks were similar after UCB (n=126), (HR 0.86, P=0.54) and URD (n=91) (HR 0.81, P=0.43). UCB HCT was associated with statistically higher non-relapse mortality compared with sibling HCT (HR 2.32, P=0.02), but not vs URD (HR 1.72, P=0.07). All three cohorts had statistically not significant 3-year LFS: 39% (95% CI 30-47) after UCB, 43% (95% CI 30-54) after sibling, and 50% (95% CI 40-60) after URD. Chronic GVHD rates were significantly lower after UCB compared with either sibling (HR 0.59, P=0.03) or URD (HR 0.49, P=0.001). Adverse factors for LFS included high leukocyte count at diagnosis and HCT during CR2. UCB is a suitable option for adults with FLT3+AML in the absence of an HLA-matched sibling and its immediate availability may be particularly important for FLT3+ AML where early relapse is common thus allowing HCT in CR1 when outcomes are best.Leukemia accepted article preview online, 25 January 2017. doi:10.1038/leu.2017.42. [less ▲]

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See detailMethane in the South China Sea and the Western Philippine Sea
Tseng, Hsiao-Chun; Chen, Chen-Tung Arthur; Borges, Alberto ULg et al

in Continental Shelf Research (2017), 135

Approximately 700 water samples from the South China Sea (SCS) and 300 water samples from the western Philippine Sea (wPS) were collected during eight cruises from August 2003 to July 2007 to determine ... [more ▼]

Approximately 700 water samples from the South China Sea (SCS) and 300 water samples from the western Philippine Sea (wPS) were collected during eight cruises from August 2003 to July 2007 to determine methane (CH4) distributions from the surface to a depth of 4250 m. The surface CH4 concentrations exceeded atmospheric equilibrium, both in the SCS and the wPS, and the concentrations were 4.5±3.6 and 3.0±1.2 nmol L−1, respectively. The sea-to-air fluxes were calculated, and the SCS and the wPS were found to emit CH4 to the atmosphere at 8.6±6.4 µmol m−2 d−1 and 4.9±4.9 µmol m−2 d−1, respectively. In the SCS, CH4 emissions were higher over the continental shelf (11.0±7.4 µmol m−2 d−1) than over the deep ocean (6.1±6.0 µmol m−2 d−1), owing to greater biological productivity and closer coupling with the sediments on the continental shelf. The SCS emitted 30.1×106 mol d−1 CH4 to the atmosphere and exported 1.82×106 mol d−1 CH4 to the wPS. The concentrations of both CH4 and chlorophyll a were high in the 150 m surface layer of the wPS, but were not significantly correlated with each other. CH4 concentrations generally declined with increasing depth below the euphotic zone but remained constant below 1,000 m, both in the SCS and the wPS. Some high CH4 concentrations were observed at mid-depths and bottom waters in the SCS, and were most likely caused by the release of CH4 from gas hydrates or gas seepage. [less ▲]

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See detailTowards a chromatographic similarity index to establish localised Quantitative Structure-Retention Relationships for retention prediction. II Use of Tanimoto similarity index in ion chromatography
Park, S. H.; Talebi, M.; Amos, R. I. J. et al

in Journal of Chromatography. A (2017)

Quantitative Structure-Retention Relationships (QSRR) are used to predict retention times of compounds based only on their chemical structures encoded by molecular descriptors. The main concern in QSRR ... [more ▼]

Quantitative Structure-Retention Relationships (QSRR) are used to predict retention times of compounds based only on their chemical structures encoded by molecular descriptors. The main concern in QSRR modelling is to build models with high predictive power, allowing reliable retention prediction for the unknown compounds across the chromatographic space. With the aim of enhancing the prediction power of the models, in this work, our previously proposed QSRR modelling approach called "federation of local models" is extended in ion chromatography to predict retention times of unknown ions, where a local model for each target ion (unknown) is created using only structurally similar ions from the dataset. A Tanimoto similarity (TS) score was utilised as a measure of structural similarity and training sets were developed by including ions that were similar to the target ion, as defined by a threshold value. The prediction of retention parameters (a- and b-values) in the linear solvent strength (LSS) model in ion chromatography, log k = a - blog[eluent], allows the prediction of retention times under all eluent concentrations. The QSRR models for a- and b-values were developed by a genetic algorithm-partial least squares method using the retention data of inorganic and small organic anions and larger organic cations (molecular mass up to 507) on four Thermo Fisher Scientific columns (AS20, AS19, AS11HC and CS17). The corresponding predicted retention times were calculated by fitting the predicted a- and b-values of the models into the LSS model equation. The predicted retention times were also plotted against the experimental values to evaluate the goodness of fit and the predictive power of the models. The application of a TS threshold of 0.6 was found to successfully produce predictive and reliable QSRR models (Qext(F2) 2 >. 0.8 and Mean Absolute Error. <. 0.1), and hence accurate retention time predictions with an average Mean Absolute Error of 0.2. min. © 2017. [less ▲]

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See detailEffect of steam explosion treatment on chemical composition and characteristic of organosolv fescue lignin
Maniet, Guillaume ULg; Schmetz, Quentin ULg; Jacquet, Nicolas ULg et al

in Industrial Crops and Products (2017), 99

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid ... [more ▼]

Tall fescue, a grass currently grown as forage, presents a good potential as a feedstock in the developmentof biorefining. In this study, combination of steam explosion and an acetic/formic acid “organosolv”pretreatments are applied on raw fescue to optimize lignin extraction yields and obtain specific products.In a first step, fescue is pretreated by steam explosion under severity factors from 1.4 to 4.2. Thesetreatments allow hemicelluloses solubilization and open the lignocellulosic structure. Steam explodedsolid residues are then treated with an acetic acid (50%)/formic acid (30%)/water (20%) mixture. Extractedlignins are precipitated and characterized by size exclusion chromatography (SEC),31P NMR and HSQCNMR. Results show that acetic and formic acids extracted lignins present G, H and S units with ferulate andp-coumarate. Lignin typical linkages identified are of -O-4 and spirodienone substructures. Combinationof steam explosion and acetic and formic acid pretreatments increases extraction yields from 30% to100%. Moreover, an increase of the steam explosion treatment intensity induces chemical modificationsin lignin structure such -O-4 and spirodienone substructure degradations, increase of free COOH andphenolic OH bonds, decrease of aliphatic OH ferulate and p-coumarate bonds and changes in G/H/S unitsproportions. Steam explosion intensity affects also lignin molecular weights. [less ▲]

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See detailEmbedded solids of any dimension in the X-FEM. Part II - Imposing Dirichlet boundary conditions
Duboeuf, Frédéric ULg; Béchet, Eric ULg

in Finite Elements in Analysis and Design (2017)

This paper focuses on the design of a stable Lagrange multiplier space dedicated to enforce Dirichlet boundary conditions on embedded boundaries of any dimension. It follows a previous paper in a series ... [more ▼]

This paper focuses on the design of a stable Lagrange multiplier space dedicated to enforce Dirichlet boundary conditions on embedded boundaries of any dimension. It follows a previous paper in a series of two, on the topic of embedded solids of any dimension within the context of the extended finite element method. While the first paper is devoted to the design of a dedicated P1 function space to solve elliptic equations defined on manifolds of codimension one or two (curves in 2D and surfaces in 3D, or curves in 3D), the general treatment of Dirichlet boundary conditions, in such a setting, remains to be addressed. This is the aim of this second paper. A new algorithm is introduced to build a stable Lagrange multiplier space from the traces of the shape functions defined on the background mesh. It is general enough to cover: (i) boundary value problems investigated in the first paper (with, for instance, Dirichlet boundary conditions defined along a line in a 3D mismatching mesh); but also (ii) those posed on manifolds of codimension zero (a domain embedded in a mesh of the same dimension) and already considered in Béchet et al. 2009. In both cases, the compatibility between the Lagrange multiplier space and that of the bulk approximation (the dedicated P1 function space used in (i), or classical shape functions used in (ii)) — resulting in the inf–sup condition — is investigate through the numerical Chapelle-Bath test. Numerical validations are performed against analytical and finite element solutions on problems involving 1D or 2D boundaries embedded in a 2D or 3D background mesh. Comparisons with Nitsche’s method and the stable Lagrange multiplier space proposed in Hautefeuille et al. 2012, when they are feasible, highlight good performance of the approach. [less ▲]

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See detailTransdifferentiation of Neuroendocrine Cells: Gangliocytoma Associated With Two Pituitary Adenomas of Different Lineage in MEN1.
Sergeant, Camille; Jublanc, Christel; Leclercq, Delphine et al

in American Journal of Surgical Pathology (2017)

Gangliocytomas are rare and benign neuronal cell tumors, mostly found in the hypothalamic and sellar regions. Their histogenesis is still the subject of discussions. Herein we present a unique case of a ... [more ▼]

Gangliocytomas are rare and benign neuronal cell tumors, mostly found in the hypothalamic and sellar regions. Their histogenesis is still the subject of discussions. Herein we present a unique case of a pituitary gangliocytoma associated with a prolactinoma and a corticotroph adenoma in a patient affected by MEN1. The histologic study revealed shared features between adenomatous and neuronal cells, supporting the etiological hypothesis of a common origin or a phenomenon of transdifferentiation. Furthermore, gangliocytoma could be a new tumor related to MEN1. The clinical and histologic observations are discussed and the literature on the topic is reviewed. [less ▲]

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See detailEuropean Network for Neglected Vectors and Vector-Borne Infections COST Action Guidelines: What Is This About and What Is This For?
Charrel, Remi N.; Lempereur, Laetitia ULg; Mihalca, Andrei D. et al

in Vector borne and zoonotic diseases (Larchmont, N.Y.) (2017), 17(1), 1

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See detailLa principauté de Liège, le droit liégeois et la mainplévie
Lagasse, Benoît ULg

Learning material (2017)

Le présent document tend à présenter le droit liégeois et les institutions politiques et juridictionnelles relatives à la principauté de Liège à la fin de l'Ancien Régime. Par ailleurs, il comporte ... [more ▼]

Le présent document tend à présenter le droit liégeois et les institutions politiques et juridictionnelles relatives à la principauté de Liège à la fin de l'Ancien Régime. Par ailleurs, il comporte quelques considérations sur la mainplévie, institution juridique spécifique au droit liégeois. [less ▲]

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See detailSeasonal characterization of the nutrients state in Oualidia Lagoon (Moroccan Atlantic coast)
Damsiri, Zainab; Natij, L.; Khalil, Karima et al

in Journal of Materials and Environmental Science (2017), 8(1), 67-77

The nutrient cycle in Oualidia lagoon, on the Atlantic Moroccan coast, was studied at both spatial and temporal scales, covering spring and summer conditions. Water samples were collected bimonthly at ... [more ▼]

The nutrient cycle in Oualidia lagoon, on the Atlantic Moroccan coast, was studied at both spatial and temporal scales, covering spring and summer conditions. Water samples were collected bimonthly at high tide from March to August during years 2011 and 2012 at six stations distributed throughout the lagoon. The physico- chemistry (temperature, salinity, dissolved O2) and nutrient enrichment of the lagoon surface water were monitored. The average nutrient concentration of surface water were 14.4 μmol.l-1 and 28.1 μmol.l-1 for NH4+, 20.4 μmol.l-1 and 19.9 μmol.l-1 for PO43- and 3.7 μmol.l-1 and 7.6 μmol.l-1 for NO2- in 2011 and 2012, respectively. Strong seasonal differences of nutrient distribution at the different stations were noticed. Temperature, salinity and dissolved O2 were correlated with nutrient concentrations, all parameters showing low spatial (inter-station) variability. Hydrological conditions exert a major control on the nutrient cycling in the lagoon. Results of this study are important to increase the richness on the scientific knowledge of nutrient dynamics along the Moroccan Atlantic coast, particularly in the semi-enclosed lagoons that are important transitional systems. [less ▲]

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See detailRetention prediction of low molecular weight anions in ion chromatography based on quantitative structure-retention relationships applied to the linear solvent strength model
Park, S. H.; Haddad, P. R.; Talebi, M. et al

in Journal of Chromatography. A (2017), 1486

Quantitative Structure-Retention Relationships (QSRRs) represent a popular technique to predict the retention times of analytes, based on molecular descriptors encoding the chemical structures of the ... [more ▼]

Quantitative Structure-Retention Relationships (QSRRs) represent a popular technique to predict the retention times of analytes, based on molecular descriptors encoding the chemical structures of the analytes. The linear solvent strength (LSS) model relating the retention factor, k to the eluent concentration (log k = a − blog [eluent]), is a well-known and accurate retention model in ion chromatography (IC). In this work, QSRRs for inorganic and small organic anions were used to predict the regression parameters a and b in the LSS model (and hence retention times) for these analytes under a wide range of eluent conditions, based solely on their chemical structures. This approach was performed on retention data of inorganic and small organic anions from the “Virtual Column” software (Thermo Fisher Scientific). These retention data were recalibrated via a “porting” methodology on three columns (AS20, AS19, and AS11HC), prior to the QSRR modeling. This provided retention data more applicable on recently produced columns which may exhibit changes of column behavior due to batch-to-batch variability. Molecular descriptors for the analytes were calculated with Dragon software using the geometry-optimized molecular structures, employing the AM1 semi-empirical method. An optimal subset of molecular descriptors was then selected using an evolutionary algorithm (EA). Finally, the QSRR models were generated by multiple linear regression (MLR). As a result, six QSRR models with good predictive performance were successfully derived for a- and b-values on three columns (R2 > 0.98 and RMSE < 0.11). External validation showed the possibility of using the developed QSRR models as predictive tools in IC (Qext(F3) 2 > 0.7 and RMSEP < 0.4). Moreover, it was demonstrated that the obtained QSRR models for the a- and b-values can predict the retention times for new analytes with good accuracy and predictability (R2 of 0.98, RMSE of 0.89 min, Qext(F3) 2 of 0.96 and RMSEP of 1.18 min). © 2016 Elsevier B.V. [less ▲]

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See detail*/'βɔstru/
Aresti, Alessandro ULg; Dworkin, Steve

in Buchi, Éva; Schweickard, Wolfgang (Eds.) Dictionnaire Étymologique Roman (DÉRom) 2. Pratique lexicographique et réflexions théoriques (2017)

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See detailDécider les politiques culturelles en démocraties : les politiques du théâtre de la Communauté française de Belgique.
Lowies, Jean-Gilles ULg

Doctoral thesis (2017)

Depuis que la Belgique existe, l’État intervient dans le secteur de la culture, il mène des politiques culturelles dont un aspect majeur consiste à octroyer des financements. Qui décide l’octroi des ... [more ▼]

Depuis que la Belgique existe, l’État intervient dans le secteur de la culture, il mène des politiques culturelles dont un aspect majeur consiste à octroyer des financements. Qui décide l’octroi des subventions ? Comment ces attributions sont-elles décidées ? Quels sont les critères de choix ? L’autonomie artistique des théâtres est elle préservée ? Quelle est la place d’un pouvoir politique démocratique dans des choix artistiques subjectifs ? Voilà quelques questions qui seront abordées au cours de cet ouvrage. Parmi nombre d’enjeux sociaux, économiques et artistiques émaillant la thématique, nous aborderons spécifiquement les liens entre culture et politique, entre l’art et l’exercice du pouvoir, c’est à dire la décision. À cette fin, la recherche se concentre sur l’analyse du processus décisionnel des politiques publiques de la Communauté française dans le domaine du théâtre, concernant principalement la période s’étalant de 2003 à 2016. Comment un État démocratique peut-il décider une action publique en matière culturelle sans prétendre au monopole de la culture légitime ? Décider les politiques culturelles en régime démocratique ne relève pas d’une évidence partagée. Il existe un paradoxe constitutif à leur existence : l’État est sommé d’ « agir sans agir » et d’être « neutre », il est appelé à œuvrer de manière impartiale dans l’intérêt des gouvernés tout en ne s’immisçant pas sur le territoire de l’autonomie artistique. À vrai dire, aucun pays ne semble avoir trouvé de système décisionnel qui paraisse satisfaire pleinement l’idéal démocratique ni, plus prosaïquement, les intérêts de toutes les parties prenantes. Chaque pays conjugue les impératifs démocratiques avec les contraintes du contexte historique, sociopolitique et culturel pour établir des institutions, des procédures et des discours aptes à asseoir et légitimer les décisions. Comment la Communauté française de Belgique tend elle à résoudre cette délicate équation dans le secteur du théâtre ? La plupart des typologies de politiques culturelles prennent en considération le degré d'indépendance entre le politique et les arts. Les politiques culturelles belges – et celles de la Communauté française de Belgique – sont généralement situées entre l’idéaltype britannique et l'idéaltype français. Pour le premier, le financement des arts est décidé par des organismes non gouvernementaux et suit le principe du arm's length, principe de non-interférence. Pour le deuxième, les décisions sont centralisées et elles sont opérées directement par l’État. La Belgique aurait développé un modèle hybride, à mi-chemin entre les grandes nations précitées. A contrario, cet ouvrage développera l’hypothèse que le système décisionnel des politiques culturelles de la Communauté française est ancré dans un régime de consociativisme, mêlant les éléments d’une société pilarisée, d’une particratie et d’institutions empreintes du principe de pluralisme idéologique et philosophique tel que consacré par le Pacte culturel de 1973. [less ▲]

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See detailEffects of isolated versus combined learning enactments in an online course
Verpoorten, Dominique ULg; Westera, Wim; Specht, Marcus

in International Journal of Technology Enhanced Learning (2017)

In a controlled experiment on the effects of frequent and local digital annotations, 137 volunteers covered an online course under three possible conditions: no/free/question-based digital annotations ... [more ▼]

In a controlled experiment on the effects of frequent and local digital annotations, 137 volunteers covered an online course under three possible conditions: no/free/question-based digital annotations. Results show no difference in performance between groups when annotation behaviour is considered in isolation. However, analyses conducted within treatments provide indications of a positive impact on performance when annotation rates are taken into consideration, and coupled with other enactments tracked in the course. Combined in engagement profiles (Learning DNAs), these enactments suggest that what makes active learning efficient might be an ongoing crisscrossing between a firstorder learning activity (the study of the course) and a series of second order activities, such as making notes. Students who manage to coordinate these activities at a higher rate perform better. This observation opens a line of reasoning about what determines the quality of a mental engagement in a learning task, in terms of balance and rotation of cognitive and metacognitive operations. [less ▲]

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See detailThe global burden of chronic kidney disease: estimates, variability and pitfalls.
Glassock, RJ; Warnock, DG; DELANAYE, Pierre ULg

in Nature Reviews Nephrology (2017), 13(2), 104-114

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See detailA dynamic, sex-specific expression pattern of genes regulating thyroid hormone action in the developing zebra finch song control system
Raymaekers, S.R.; Verbeure, W.; Ter Haar, S.M. et al

in General and Comparative Endocrinology (2017), 240

The zebra finch (Taeniopygia guttata) song control system consists of several series of interconnected brain nuclei that undergo marked changes during ontogeny and sexual development, making it an excel ... [more ▼]

The zebra finch (Taeniopygia guttata) song control system consists of several series of interconnected brain nuclei that undergo marked changes during ontogeny and sexual development, making it an excel- lent model to study developmental neuroplasticity. Despite the demonstrated influence of hormones such as sex steroids on this phenomenon, thyroid hormones (THs) – an important factor in neural devel- opment and maturation – have not been studied in this regard. We used in situ hybridization to compare the expression of TH transporters, deiodinases and receptors between both sexes during all phases of song development in male zebra finch. Comparisons were made in four song control nuclei: Area X, the lateral magnocellular nucleus of the anterior nidopallium (LMAN), HVC (used as proper name) and the robust nucleus of the arcopallium (RA). Most genes regulating TH action are expressed in these four nuclei at early stages of development. However, while general expression levels decrease with age, the activating enzyme deiodinase type 2 remains highly expressed in Area X, HVC and RA in males, but not in females, until 90days post-hatch (dph), which marks the end of sensorimotor learning. Furthermore, the L-type amino acid transporter 1 and TH receptor beta show elevated expression in male HVC and RA respectively compared to surrounding tissue until adulthood. Differences compared to sur- rounding tissue and between sexes for the other TH regulators were minor. These developmental changes are accompanied by a strong local increase in vascularization in the male RA between 20 and 30 dph but not in Area X or HVC. Our results suggest that local regulation of TH signaling is an important factor in the development of the song control nuclei during the song learning phase and that TH activation by DIO2 is a key player in this process. [less ▲]

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See detailA water retention model for compacted bentonites
Dieudonné, Anne-Catherine ULg; Della Vecchia, Gabriele; Charlier, Robert ULg

in Canadian Geotechnical Journal (2017)

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See detailA robust statistical approach to select adequate error distributions for financial returns
Hambuckers, julien ULg; Heuchenne, Cédric ULg

in Journal of Applied Statistics (2017), 44(1), 137-161

In this article, we propose a robust statistical approach to select an appropriate error distribution, in a classical multiplicative heteroscedastic model. In a first step, unlike to the traditional ... [more ▼]

In this article, we propose a robust statistical approach to select an appropriate error distribution, in a classical multiplicative heteroscedastic model. In a first step, unlike to the traditional approach, we don't use any GARCH-type estimation of the conditional variance. Instead, we propose to use a recently developed nonparametric procedure (Mercurio and Spokoiny, 2004): the Local Adaptive Volatility Estimation (LAVE). The motivation for using this method is to avoid a possible model misspecification for the conditional variance. In a second step, we suggest a set of estimation and model selection procedures (Berk-Jones tests, kernel density-based selection, censored likelihood score, coverage probability) based on the so-obtained residuals. These methods enable to assess the global fit of a set of distributions as well as to focus on their behavior in the tails, giving us the capacity to map the strengths and weaknesses of the candidate distributions. A bootstrap procedure is provided to compute the rejection regions in this semiparametric context. Finally, we illustrate our methodology throughout a small simulation study and an application on three time series of daily returns (UBS stock returns, BOVESPA returns and EUR/USD exchange rates) [less ▲]

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See detailFactors controlling spatial and temporal patterns of multiple pesticide compounds in groundwater (Hesbaye chalk aquifer, Belgium)
Hakoun, Vivien; Orban, Philippe ULg; Dassargues, Alain ULg et al

in Environmental Pollution (2017)

Factors governing spatial and temporal patterns of pesticide compounds (pesticides and metabolites) concentrations in chalk aquifers remain unclear due to complex flow processes and multiple sources. To ... [more ▼]

Factors governing spatial and temporal patterns of pesticide compounds (pesticides and metabolites) concentrations in chalk aquifers remain unclear due to complex flow processes and multiple sources. To uncover which factors govern pesticide compound concentrations in a chalk aquifer, we develop a methodology based on time series analyses, uni- and multivariate statistics accounting for concentrations below detection limits. The methodology is applied to long records (1996–2013) of a restricted compound (bentazone), three banned compounds (atrazine, diuron and simazine) and two metabolites (deethylatrazine (DEA) and 2,6–dichlorobenzamide (BAM)) sampled in the Hesbaye chalk aquifer in Belgium. In the confined area, all compounds had non-detects fractions >80%. By contrast, maximum concentrations exceeded EU’s drinking-water standard (100 ngL-1) in the unconfined area. This contrast confirms that recent recharge and polluted water did not reach the confined area, yet. Multivariate analyses based on variables representative of the hydrogeological setting revealed higher diuron and simazine concentrations in the southeast of the unconfined area, where urban activities dominate land use and where the aquifer lacks protection from a less permeable layer of hardened chalk. At individual sites, positive correlations (up to τ =0,48 for bentazone) between pesticide compound concentrations and multi-annual groundwater level fluctuations confirm occurrences of remobilization. A downward temporal trend of atrazine concentrations likely reflects decreasing use of this compound over the last 28 years. However, the lack of a break in concentrations time series and maximum concentrations of atrazine, simazine, DEA and BAM exceeding EU’s standard post-ban years provide evidence of persistence. Contrasting upward trends in bentazone concentrations show that a time lag is required for restriction measures to be efficient. These results shed light on factors governing pesticide compound concentrations in chalk aquifers. The developed methodology is not restricted to chalk aquifers, it could be transposed to study other pollutants with concentrations below detection limits. Several factors govern pesticide compounds concentrations in the chalk: hydrogeological setting, land use, groundwater level fluctuations and persistence. [less ▲]

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