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Bouzelboudjen, Mahmoud

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Bouzelboudjen, Mahmoud
Affiliation principale
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Ancien.ne collaborateur.trice
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https://libra.unine.ch/handle/123456789/1079

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  • Publication
    Accès libre
    Serological signature of tick-borne pathogens in Scandinavian brown bears over two decades
    (2015-7-28)
    Paillard, Lye 
    ;
    Jones, Krista L.
    ;
    Evans, Alina L.
    ;
    Jacquet, Maxime 
    ;
    Berret, Jérémy 
    ;
    Lienhard, Reto
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Arnemo, Jon M.
    ;
    Swenson, Jon E.
    ;
    Voordouw, Maarten 
    Background: Anthropogenic disturbances are changing the geographic distribution of ticks and tick-borne diseases. Over the last few decades, the tick Ixodes ricinus has expanded its range and abundance considerably in northern Europe. Concurrently, the incidence of tick-borne diseases, such as Lyme borreliosis and tick-borne encephalitis, has increased in the human populations of the Scandinavian countries. Methods: Wildlife populations can serve as sentinels for changes in the distribution of tick-borne diseases. We used serum samples from a long-term study on the Scandinavian brown bear, Ursus arctos, and standard immunological methods to test whether exposure to Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis, and tick-borne encephalitis virus (TBEV) had increased over time. Bears had been sampled over a period of 18 years (1995-2012) from a southern area, where Ixodes ricinus ticks are present, and a northern area where ticks are uncommon or absent. Results: Bears had high levels of IgG antibodies against B. burgdorferi sensu lato but not TBEV. Bears at the southern area had higher values of anti-Borrelia IgG antibodies than bears at the northern area. Over the duration of the study, the value of anti-Borrelia IgG antibodies increased in the southern area but not the northern area. Anti-Borrelia IgG antibodies increased with the age of the bear but declined in the oldest age classes. Conclusions: Our study is consistent with the view that ticks and tick-borne pathogens are expanding their abundance and prevalence in Scandinavia. Long-term serological monitoring of large mammals can provide insight into how anthropogenic disturbances are changing the distribution of ticks and tick-borne diseases.
  • Publication
    Accès libre
    Spatial Group Structure as Potential Mechanism to Maintain Cooperation in Fish Shoals of Unrelated Individuals
    (2012)
    Cisarovsky, Gabriel
    ;
    Bshary, Andrea 
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Bshary, Redouan 
    In public goods games, group members share the benefits created through individual investments. If benefits are shared equally, individual contributions readily become altruistic, and hence, a social dilemma arises in which group interests and individual interests oppose each other. However, contributions to public goods can be self-serving if each investor gains a disproportionate benefit from its own contribution. This scenario may hold for our study system, the interactions of shoaling-unrelated scalefin anthias Pseudanthias squamipinnis and the ectoparasitic blenny Plagiotremus tapeinosoma. The blenny bites off pieces of skin, mucus and scales from anthias that in return may chase the blenny. Chasing the blenny represents a public good as it makes the parasite change victim species for its next attack. Laboratory experiments using artificial Plexiglas hosts suggest that one reason why individuals contribute to the public good is that the blenny may specialise on non-punishing ‘free-riders’. Here, we investigated how far a spatial structure within the shoal and limited space use by the blenny may contribute to punishment being self-serving. Field observation reveals that anthias indeed live in spatially structured groups and that blennies have preferred areas for attacks. Thus, some anthias individuals are consistently more exposed to blennies than others and hence may gain disproportional benefits from their punishment. In conclusion, spatial structure may contribute to the maintenance of punishment in blenny–anthias interactions even when groups are large.
  • Publication
    Accès libre
    The modelling of soil-process functional units based on three-dimensional soil horizon cartography, with an example of denitrification in a riparian zone
    (2003)
    Cosandey, Anne-Claude
    ;
    Guenat, Claire
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Maı̂tre, Véronique
    ;
    Bovier, Raphaël
    This article aims to propose an approach for estimating the three-dimensional (3D) variability of denitrification. The concept of functional horizons is applied to the process of biological denitrification and 3D soil horizon cartography is used to estimate its spatial variation. On one hand, detailed fieldwork (186 pedological auger holes) was undertaken to map 3D horizon distribution within a 3-ha riparian area using Geographical Information Systems (GIS). On the other hand, three classes of denitrifying capacities were defined according to the distribution of the denitrifying enzyme activity of 51 samples. The relationship between the process of denitrification and the cartography is assessed through soil characteristics, which both differentiate soil horizons and control the process of denitrification: organic carbon and textural fractions. This allows a class of denitrifying capacity to be attributed to each soil horizon. This information was inserted into the 3D soil horizon cartography and the denitrifying functional horizons could be delimited. With this approach, field criteria are used and variations of the 3D distribution of denitrification are considered in order to estimate the spatial variation of denitrification within the riparian area being studied.
  • Publication
    Accès libre
    Contribution d'un système d'information à référence spatiale à la sélection de sites potentiels de stockage de déchets ménagers et industriels en région semi-aride (Souss, Maroc)
    (2003)
    El Morjani, Zine El Abidine
    ;
    Wildi, Walter
    ;
    Jaquet, Jean-Michel
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Bouchaou, Lhoussaine
    La gestion de l'environnement dans un esprit de développement durable est un besoin vital de notre société. Sa mise en oeuvre exige une approche pluridisciplinaire et interdisciplinaire, sur la base d'un concept approprié, ainsi que d'une base de données exhaustive. Dans ce cadre, il est indispensable d'acquérir des informations détaillées, fiables et bien organisées sur l'état de l'environnement et du territoire. Le projet SIRS Souss (SIRSS) vise à élaborer une approche optimale de gestion de l'environnement intégrant le concept de développement durable. Il permet la spatialisation des différents facteurs techniques, environnementaux, sociaux et économiques tout en mettant en oeuvre des outils modernes d'analyse et de modélisation.
    Le point central de ce travail concerne l'élaboration de données numériques spatiales et temporelles, contenant les informations ayant un rapport avec la gestion environnementale et l'aménagement du territoire dans la région du Souss (Sud Marocain). Cette recherche a permis la création de six documents spatiaux de base en format raster ou vecteur (la topographie, la couverture du sol, la lithologie, la pédologie, la population et la piézométrie du bassin) et l'établissement de six cartes mensuelles hydro-climatiques en format raster résultat d’une simulation de la continuité spatiale des principaux processus hydrologiques : précipitations, températures, aridité, évapotranspiration, ruissellement et infiltration. Comme méta-information, nous avons associé des cartes d'évaluation de la "qualité" des estimations. Cette méthodologie spatiale a nécessité des approches déterministes et probabilistes et le recours à diverses méthodes statistiques (régression multiple, analyse en composantes principales). La combinaison des Systèmes d'Information à Référence Spatiale (SIRS) et la télédétection (TD) représente un apport original et incontestable. Ce système d'information met à la disposition des ingénieurs et gestionnaires des outils d'analyse et d'aide à la décision pour l'aménagement et la planification du territoire.
    Dans le cadre de cette recherche, une démarche intégrée de traitement numérique des données spatiales a été appliquée en vue d’une sélection des meilleures installations pour le stockage des déchets ménagers et industriels (ISDMI) dans le bassin du Souss. Cette application a été motivée par les résultats d’une évaluation des risques environnementaux liés à la décharge actuelle du Grand Agadir, considérant celle-ci comme une source de danger potentiel pour la santé de la population riveraine et l'environnement. Le SIRS et l'analyse multicritère (AM) se sont avérés être des outils et des méthodes bien adaptés à cette nouvelle problématique de nature éminemment multidisciplinaire. Le SIRS a contribué à l'évaluation d'un grand nombre d'alternatives pour la localisation d’ISDMI selon les critères d'évaluation (critères exclusifs et d'appréciation) et les méthodes d'analyse multicritères ont été utilisées, d'une part pour faire ressortir les sites les plus adéquats au stockage des déchets ménagers et, d'autre part, établir une liste de priorité pour les sites potentiels de stockage des déchets industriels non dangereux.
  • Publication
    Accès libre
    3-D groundwater modeling at regional scale
    (2001)
    Kimmeier, Francesco
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Király, László
    Large hydrogeological basins are constituted of several superimposed aquifers, separated by geological formations of relatively low permeabilities. The delimitation of the different flow systems is far more difficult to realize for a heterogeneous system. Flux vectors provide valuable indications about groundwater flow paths and hydraulic exchanges between the different geological formations. Hydraulic relationships between two superimposed aquifers can vary locally: an aquifer can «feed» the underlying one at some point and conversely elsewhere. These relationships, which constitute in fact the flow field, will be determined by the structure of the basin as defined by the spatial distribution of the rock permeabilities, and by the boundary conditions, as defined by the locations of the recharge and discharge areas. The aim of this study is to show schematically the deep groundwater flow patterns between the massives of the Aar and the Black Forest. The hydrogeological profiles illustrate three-dimensional flow fields inside a large volume of terrain and represent but one of the numerous solutions of the mathematical modelling realized. Computations have been performed for a steady state flow regime, which means that the boundary conditions do not vary with time.
    On the basis of modelling results, it was possible to illustrate schematically the deep flow systems of the most important aquifers between the Aar massives and the Black Forest (Malm, Muschelkalk and upper Cristallin). An approximate but plausible representation of the groundwater circulation in deep aquifers was obtained thanks to the model. We are able to distinguish between the hydraulic relationships of two superimposed aquifers in various regions. The three-dimensional representation shows the outcrop zones of the different geological formations as well as the situation of recharge areas, which are characterised by high potentials, and discharge zones, which are characterised by low potentials in valleys represented by the hydrographic network.
    Modelling results are then compared to available measurements in an attempt to validate the results. It is interesting to notice that it was possible, to a certain extent, to verify the modelling results by deep drillings. Most particularly, measurements of the hydraulic potentials at various depths in these boreholes have revealed upwellings close to the regional discharge areas.
  • Publication
    Accès libre
    3-D Groundwater Flow Modeling in Heterogeneous Geologic Media: an Integrated Approach Using Spatial and Temporal Database, Geostatistics and GIS
    (Neuchâtel : Université de Neuchâtel, 2001)
    Kimmeier, Francesco
    ;
    Kiraly, Lazlo
    ;
    Bouzelboudjen, Mahmoud 
    L'objectif de ce travail est de présenter, à travers plusieurs articles et plusieurs approches, l'identification des systèmes hydrogéologiques dans la résolution de problèmes pratiques. Une partie majeure de ce travail montre l'évolution des méthodes et des techniques numériques les plus récentes essentiellement dans l'organisation des données hydrogéologiques spatiales et temporelles, la re-construction des divers champs structuraux et hydrodynamiques jusqu'aux traitement et représentation des résultats des simulations numériques tridimensionnelles des écoulements souterrains par la méthode des éléments finis. Les approches que nous avons utilisées sont globales ou empiriques, déterministes ou stochastiques. La combinaison des techniques des systèmes d'information géographique, de géostatistique, et de simulation numérique déterministe des écoulements souterrains, représente un apport original et indéniable. Cette démarche intégrée du traitement numérique des données spatiales nous a permis de proposer un modèle mathématique 3-D opérationnel, dans la région de Visp (Valais), permettant la gestion des eaux souterraines. De plus, on peut noter trois thèmes abordés à travers les articles intégrés dans la thèse. Le premier traite des aspects de la création d'une base de données tabulaires reliée à un système d'information géographique dans un environnement du karst neuchâtelois. Le second montre les limites des méthodes classiques empiriques dans l'étude de la vulnérabilité des aquifères à la pollution. Le troisième permet d'évaluer l'incertitude des trajectoires en terme de migration de polluant par combinaison de modèles déterministes d'écoulement et des modèles probabilistes
  • Publication
    Accès libre
    Travel path uncertainty: a case study combining stochastic and deterministic hydrodynamic models in the Rhône valley, Switzerland
    (2001)
    Kimmeier, Francesco
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Ababou, Rachid
    ;
    Ribeiro, Luis
    In the framework of waste storage in geological formations at shallow or greater depths and accidental pollution, the numerical simulation of groundwater flow and contaminant transport represents an important instrument to predict and quantify the pollution as a function of time and space. The numerical simulation problem, and the required hydrogeologic data, are often approached in a deterministic fashion. However, deterministic models do not allow to evaluate the uncertainty of results. Furthermore, the hydrogeologic data and hydrodynamic properties required to implement the flow-transport model are generally very scant, so that an essential part of the simulation effort needs to be devoted to building the different spatially distributed data through spatial interpolation, extrapolation, smoothing, etc. In this paper, deterministic (classic finite element hydrodynamic model) and stochastic approaches (geostatistics : kriging and conditional simulations) are used for evaluating groundwater flow patterns and pollutant trajectories for a site-specific application (Rhône valley aquifer in Switzerland, area of 6.5 km2). The stochastic approach, based on kriging and multiple conditional simulations, leads to a quantification of uncertainty of flow-transport simulations, which are due to the underlying uncertainty of hydrogeologic properties and their spatial distribution. The available data used in this case study are : 55 transmissivity, 791 permeability and 145 hydraulic potential values. In spite of the relative wealth of available data, our study shows that the uncertainty of pollutant migration pathlines and travel distances is relatively important. The distance traveled by a pollutant particle during 30 monthes varies between 3150 m and 4800 m over five different but equally plausible scenarios (conditional simulations). The uncertainty is about 42% relative to the average travel distance, or 55% relative to the smallest travel distance mentioned above.
  • Publication
    Accès libre
    Geohydrological parameters identification and groundwater vulnerability to pollution: A Swiss case study
    (2001)
    Kimmeier, Francesco
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Ornstein, Pascal
    ;
    Weber, Isabelle
    ;
    Rouiller, Jean-Daniel
    The alluvial aquifer of the Rhône valley in Switzerland, which extends over 110 km and occupies an area of 256 km2, is of great economic importance. Its groundwaters are easily accessible and thus exploitable at low cost. However, its location in an often narrow valley with intense human activity (industry, agriculture, communications network) makes it particularly vulnerable from both a qualitative (industrial and\or agricultural pollution) and quantitative point of view (groundwater flow disturbance following civil engineering works). Since 1995, the Swiss canton of Valais has decided to compile datasets from a number of local studies (water supply, hydro-electricity, and geotechnical studies) into a regional, integrated hydrogeological framework. The realization of the study has shown the importance of GIS tool either for the computing and mapping of the first piezometric map between Brig and Léman Lake or the elaboration of vulnerability maps. The geostatistic tool was also intensively used all over the spatial treatment of data. The comparison of groundwaters NO3-- content (1985 and 1995), has shown that globally the nitrates content in the groundwater is low (< 30 mg/l for 90 % of samples). However it must be notice that the evolution of the NO3-- content degrades during time. The study of vulnerability to pollution for the aquifer situated between Sierre and Vétroz as shown significant differences between the four different methods used. As main results DRASTIC and SINTACS integrated methods are concentrated between Moderate and High vulnerability when NLFB and GOD intrinsic methods are concentrated between Very Low and Moderate vulnerability. Intrinsic methods have the tendency to minimize the vulnerability.
  • Publication
    Accès libre
    Drought risk analysis applied to porous Swiss aquifers
    (2001)
    Kimmeier, Francesco
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Eisenlohr, Laurent
    ;
    Rossier, Yvan
    The impact of hydrogeological drought on groundwater has been studied in the context of natural flow systems. The aim of this article is to find the relative resistance of 18 unconfined aquifer systems in porous media to a prolonged shortfall in recharge. A synthetic relative drought resistance indicator has been calculated for each of the aquifer systems based on 4 variables which are the half-recession time, the specific regulatory capacity, the drainage density and the aquifer system area.
    The analysis shows that 33% of the chosen aquifer systems are weakly resistant. By contrast, 22% have a high drought resistance. The other aquifer systems are of moderate resistance (22%) or of good resistance (22%).
  • Publication
    Accès libre
    Contribution of a GIS in the spatial modeling of the hydrologic balance of Allondon watershed (France, Switzerland)
    (2001)
    Ebener, Steeve
    ;
    Wildi, Walter
    ;
    Bouzelboudjen, Mahmoud 
    ;
    Jaquet, J-M
    ;
    Fortin, J.-P
    This paper discusses the development of an approach allowing the spatial distribution of the hydrologic balance at the watershed scale using Geographical Information Systems (GIS). Methods were developed in order to obtain the intensity distribution of precipitation, interception, infiltration, runoff and evapotranspiration. These methods have been applied on the Allondon watershed (France, Switzerland). At the scale of this watershed (142 km2), the annual input of rain reaches 190*106m3, the snow melt contributing to 4*106m3 to this amount. Vegetation intercepts 26*106m3 from which 8*106m3 aren’t evapotranspired but reaching the ground. On the ground surface, 176*106m3 are divided into runoff for 92*106m3 and infiltration for 84*106m3. The evapotranspiration generates a return of 61*106m3 in the atmosphere. This volume of water comes from interception and from the stock observed in the soils.