A modular approach to the Korba aquifer seawater intrusion study, 1, GIS field data analysis

Seawater intrusion is an important environmental problem in the coastal aquifers of many Mediterranean countries. In the 438 km2 Korba aquifer in eastern Tunisia, a large increase in the number of pumping wells for irrigation purposes since the 1960s has resulted in a lowering to below sea level of the water table in several observation piezometers, and in a consequent deterioration of the water quality. Several remediation scenarios are being considered for this region, including rationalization and control of water pumping from the wells, artificial recharge of the aquifer and construction of small dams to serve as an alternative source of irrigation water. In order to investigate the impact of these measures on the aquifer water quality, a GIS-based modeling study is being undertaken. The available data set comprises a number of layers of geographical information, giving a complete hy-drogeological characterization of the region, and time series of chemical and hydrologic variables acquired during several ground sampling campaigns performed in the last thirty years. The GIS is used to organize this heterogeneous data structure and to control the data flow through various phases of the work, i.e. the pre-processing of input data for the model, the interpretation of model outputs, and the calibration of the model itself. The GIS serves also as a support tool in the genera-tion of the 3-D computational grid used in the numerical simulations. In addition to describing the data structure and the organization of the system, the paper illustrates also the implementation of a simple recharge optimization scenario

Analysis of seawater intrusion phenomena in the Korba coastal aquifer of Tunisia

A geographic information system and a three-dimensional coupled variable density and saturation numerical model are implemented for the Korba coastal aquifer of northeastern Tunisia, and preliminary simulations are performed to investigate seawater intrusion phenomena. The GIS provides an essential platform for data management, enabling the organization and merging of a large volume of data that has been collected in often ad hoc manner from diverse sources over many years. A critical assessment of data quality is provided and the usefulness of GIS and modeling tools is demonstrated, with an aim to encourage more directed and continuous monitoring and characterization of important parameters and processes involved in the contamination phenomena. This approach is currently being extended to two other coastal aquifers, in Sardinia (Italy) and Sahel (Morocco).51-5

Modeling and Analysis of Seawater Intrusion in the Coastal Aquifer of Eastern Cap-Bon, Tunisia

A numerical model that treats density-dependent variably saturated flow and miscible salt transport is used to investigate the occurrence of seawater intrusion in the ‘Korba’ aquifer of the eastern coast of Cap-Bon in northern Tunisia. We examine the interplay between pumping regimes and recharge scenarios and its effect on the saline water distribution. More localized simulations are used to examine, in vertical cross sections, the effects of well location and soil type and the role of the vadose zone in possible remediation actions. The exploratory simulations suggest interesting interactions between the unsaturated zone and the saltwater–freshwater interface with possible implications for groundwater exploitation from shallow unconfined coastal aquifers, involving in one case feedback between seawater intrusion and the high pressure head gradients around the pumping-induced drawdown cone and in another case threshold-like interface displacement for tight soils such as clays. The data processing steps undertaken in this GIS and modeling study are described in some detail, and a critical assessment is given of the data availability and of the requirements for successful monitoring and modeling of seawater intrusion risks in heavily exploited coastal aquifers such as those found in the semi-arid regions of the Mediterranean basin. It is shown how, with the aid of GIS, reasonably reliable information can be assembled from maps, surveys, and other sources of geospatial and hydrogeological data, an approach that is necessary in the many regions of the world with acute water resource problems but with limited means for undertaking systematic data acquisition and environmental monitoring actions. Nonetheless the need for more concerted monitoring of relevant parameters and processes and of closer coordination between monitoring and modeling is stressed. An idea of the extent of over-exploitation of the Korba aquifer is obtained by examining the pumping and rainfall/infiltration data, and the simulation results support groundwater pumping as the mechanism for and seawater intrusion as the origin of the salt contamination observed in the soils and subsurface waters of the Korba plain.3-28Pubblicat

Étude préliminaire de détection et classification des sons de la déglutition

The diseases affecting and altering the swallowing process are multi-faceted, affecting the patient’s quality of life and ability to perform well in society. The exact nature and severity of the pre/post-treatment changes depend on the location of the anomaly. Effective swallowing rehabilitation, clinically depends on the inclusion of a video-fluoroscopic evaluation of the patient’s swallowing in the post-treatment evaluation. There are other available means such as endoscopic optical fibre. The drawback of these evaluation approaches is that they are very invasive. However, these methods make it possible to observe the swallowing process and identify areas of dysfunction during the process with high accuracy. "Prevention is better than cure" is the fundamental principle of medicine in general. In this context, this thesis focuses on remote monitoring of patients and more specifically monitoring the functional evolution of the swallowing process of people at risk of dysphagia, whether at home or in medical institutions, using the minimum number of non-invasive sensors. This has motivated the monitoring of the swallowing process based on the capturing only the acoustic signature of the process and modeling the process as a sequence of acoustic events occuring within a specific time frame. The main problem of such acoustic signal processing is the automatic detection of the relevent sound signals, a crucial step in the automatic classification of sounds during food intake for automatic monitoring. The detection of relevant signal reduces the complexity of the subsequent analysis and characterisation of a particular swallowing process. The-state-of-the-art algorithms processing the detection of the swallowing sounds as distinguished from environmental noise were not sufficiently accurate. Hence, the idea occured of using an adaptive threshold on the signal resulting from wavelet decomposition. The issues related to the classification of sounds in general and swallowing sounds in particular are addressed in this work with a hierarchical analysis that aims to first identify the swallowing sound segments and then to decompose them into three characteristic sounds, consistent with the physiology of the process. The coupling between detection and classification is also addressed in this work. The real-time implementation of the detection algorithm has been carried out. However, clinical use of the classification is discussed with a plan for its staged deployment subject to normal processes of clinical approval.Les maladies altérant le processus de la déglutition sont multiples, affectant la qualité de vie du patient et sa capacité de fonctionner en société. La nature exacte et la gravité des changements post/pré-traitement dépendent de la localisation de l’anomalie. Une réadaptation efficace de la déglutition, cliniquement parlant, dépend généralement de l’inclusion d’une évaluation vidéo-fluoroscopique de la déglutition du patient dans l’évaluation post-traitement des patients en risque de fausse route. La restriction de cette utilisation est due au fait qu’elle est très invasive, comme d’autres moyens disponibles, tels que la fibre optique endoscopique. Ces méthodes permettent d’observer le déroulement de la déglutition et d’identifier les lieux de dysfonctionnement, durant ce processus, avec une précision élevée. "Mieux vaut prévenir que guérir" est le principe de base de la médecine en général. C’est dans ce contexte que se situe ce travail de thèse pour la télésurveillance des malades et plus spécifiquement pour suivre l’évolution fonctionnelle du processus de la déglutition chez des personnes à risques dysphagiques, que ce soit à domicile ou bien en institution, en utilisant le minimum de capteurs non-invasifs. C’est pourquoi le principal signal traité dans ce travail est le son. La principale problématique du traitement du signal sonore est la détection automatique du signal utile du son, étape cruciale pour la classification automatique de sons durant la prise alimentaire, en vue de la surveillance automatique. L’étape de la détection du signal utile permet de réduire la complexité du système d’analyse sonore. Les algorithmes issus de l’état de l’art traitant la détection du son de la déglutition dans le bruit environnemental n’ont pas montré une bonne performance. D’où l’idée d’utiliser un seuil adaptatif sur le signal, résultant de la décomposition en ondelettes. Les problématiques liées à la classification des sons en général et des sons de la déglutition en particulier sont abordées dans ce travail avec une analyse hiérarchique, qui vise à identifier dans un premier temps les segments de sons de la déglutition, puis à le décomposer en trois sons caractéristiques, ce qui correspond parfaitement à la physiologie du processus. Le couplage est également abordé dans ce travail. L’implémentation en temps réel de l’algorithme de détection a été réalisée. Cependant, celle de l’algorithme de classification reste en perspective. Son utilisation en clinique est prévue

Non-institutionnal foreign students in France : the ‘‘forgotten’’ that analyze their academic failure

Bien que les recherches sur l'échec universitaire ne cessent de se multiplier, très peu se sont penchées sur celui des étudiants étrangers en France. C’est pourquoi la présente thèse vise à analyser les causes évoquées par ces étudiants pour expliquer leur échec ainsi que l’éventuel impact de leur culture d’origine sur leurs démarches attributionnelles. Pour répondre à cette interrogation, nous nous sommes inscrit dans le champ de la psychologie sociale, notamment avec la théorie de l'attribution causale. Cette dernière, qui constituera notre principale référence théorique, nous permettra d’appréhender la problématique de l'échec universitaire de ces étudiants. En outre, nous en avons étudié la genèse et l’évolution conceptuelle et paradigmatique en nous inspirant, pour des raisons épistémologiques et méthodologiques, du modèle attributionnel de Heider (1958) ainsi que de celui de Weiner (1986, 1992, 1994). Conscient à la fois de la complexité d’une démarche psychosociale en dehors d’une situation expérimentale et de l’importance de donner la parole aux acteurs, nous avons décidé d’entreprendre ce travail en nous basant sur des faits réels, à travers des entretiens avec des étudiants étrangers en situation d’échec universitaire.Although research on academic failure continues to grow, very few studies have been conducted on foreign students in France. Therefore this thesis aims at analyzing the reasons the students gave to explain their failure and the potential impact of culture on their attributional approaches. To answer this question, we relied on a theoretical framework by considering psychosocial obedience, including the theory of causal attribution. The latter, which will be our main theoretical reference, will allow us to cast light on these students’ academic failure. Furthermore we studied the genesis and conceptual and pragmatical evolution of this theory by basing ourselves for epistemological and methodological reasons on Heider’s attribution theory (1958) as well Weiner’s (1986, 1992, 1994). Aware of both the complexity of a psychosocial approach outside of an experimental situation and the importance of giving a voice to those directly concerned we decided to use factual information rely on real-life cases through interviews with foreign students experiencing academic failure

Place des produits matures dans l'industrie pharmaceutique (développements et stratégies à adopter)

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Estimation des sources de pollution atmosphérique par modélisation inversée

PARIS12-Bib. électronique (940280011) / SudocSudocFranceF

Automatic Detection and Recognition of Swallowing Sounds

This paper proposes a non-invasive, acoustic-based method to i) automatically detect sounds through a neckworn microphone providing a stream of acoustic input comprising of a) swallowing-related, b) speech and c) other ambient sounds (noise); ii) classify and detect swallowing-related sounds, speech or ambient noise within the acoustic stream. The above three types of acoustic signals were recorded from subjects, without any clinical symptoms of dysphagia, with a microphone attached to the neck at a pre-studied position midway between the Laryngeal Prominence and the Jugular Notch. Frequency-based analysis detection algorithms were developed to distinguish the above three types of acoustic signals with an accuracy of 86.09%. Integrated automatic detection algorithms with classification based on Gaussian Mixture Model (GMM) using the Expectation Maximisation algorithm (EM), achieved an overall validated recognition rate of 87.60% which increased to 88.87 recognition accuracy if the validated false alarm classifications were also to be included. The proposed approach thus enables the recovery from ambient signals, detection and time-stamping of the acoustic footprints of the swallowing process chain and thus further analytics to characterise the swallowing process in terms of consistency, normality and possibly risk-assessing and localising the level of any swallowing abnormality i.e. the dysphagia. As such this helps reduce the need for invasive techniques for examination and evaluation of patient’s swallowing process and enables diagnostic clinical evaluation based only on acoustic data analytics and non-invasive clinical observations

Les inégalités spatiales de la qualité de l'air dans l'agglomération de Sfax et ses environs : Le cas des températures, de la brise, du CO et SO2 .

19 p.International audienc