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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desktop videoconferencing systems for tutorial support

Hearnshaw, David Paul January 1999 (has links)
No description available.
2

Relación entre la neumonía intrahospitalaria y la disfunción del músculo diafragma en pacientes post desorden vásculo cerebral isquémico en fase hospitalaria 2015

Tito Mallqui, Bryan Dalmacio January 2016 (has links)
Objetivos: El presente estudio tuvo como objetivo determinar la relación entre la neumonía intrahospitalaria y la disfunción del musculo diafragma en pacientes post desorden vásculo cerebral isquémico en fase hospitalaria del año 2015. Materiales y métodos: tipo de estudio observacional de tipo transversal, descriptivo, prospectivo, correlacional; se utilizó un espirómetro proporcionado por el hospital, se contó con la participación de 35 pacientes del mismo hospital y se obtuvieron los datos personales y diagnósticos de la revisión de las historias clínicas. Los pacientes fueron reclutados desde el mes de Julio hasta Diciembre del 2015, y se les realizó la prueba de espirometría por única vez. Principales medidas de resultado: se midió la Capacidad Vital Forzada (FVC) y Volumen Espiratorio Máximo en el primer segundo (FEV1) para determinar presencia/ausencia de disfunción diafragmática. Se confirmó la presencia/ausencia de neumonía intrahospitalaria con la revisión de las historias clínicas. Resultados: se determinó asociación entre disfunción diafragmática y neumonía intrahospitalaria (p<0.05). Así mismo, se estimó el OR = 10.909 (IC95%: 1.185 - 100.411). Conclusiones: Se determinó relación entre la disfunción diafragmática y la neumonía intrahospitalaria estadísticamente significativa. La disfunción diafragmática varía de persona a persona, siendo así que la mayoría de los participantes presentaron disfunción diafragmática. Las personas de mayor edad tienen más riesgo de presentar neumonía intrahospitalaria y disfunción diafragmática. Palabras clave: Neumonía intrahospitalaria (NIH), Disfunción del músculo diafragma, Desorden Vásculo Cerebral (DVC) Isquémico / --- Objetives: This investigation aimed to determine the relationship between nosocomial pneumoniae and dysfunction of diaphragm muscle in nosocomial patients with acute ischemic stroke – 2015. Materials and Methods: this investigation was an observational, cross – sectional, descriptive, prospective, correlational study; we used a hospital’s spirometer, 35 persons decided to participate, we got the personal information and obtained diagnoses of medical history. Patients were recruited from July to December – 2015, and ther performed a spirometic test just one time. Main outcome measures: we measured Forced Vital Capacity (FVC) and Forced Expiratory Volume in the first second (FEV1) to determinate presence/absence for diaphragmatic dysfuction. We confirmed presence/absence for nosocomial pneumoniae through review of medical history. Results: We determined an asociation between diaphragmatic dysfuction and nosocomial pneumoniae (p<0.05). Also, we calculated OR = 10.909 (IC 95%:1.185 – 100.411) Conclusions: we determined a relationship between diaphragmatic dysfuction and nosocomial pneumoniae statistically significant. Diaphragmatic dysfuction varies from person to person, most patients performed diaphragmatic dysfuction. Elderly people have more risk to perform nosocomial pneumoniae and diaphragmatic dysfuction. Keywords: nosocomial pneumoniae, diaphragmatic dysfuction, acute ischemic stroke.
3

The relational nature of mentoring gifted children using desktop videoconferencing

Lamont, Katrina January 2004 (has links)
The integration of technology into classrooms, the education of gifted learners, and the challenge this presents to classroom relationships as a result of engaging with computer technology are significant issues for teachers in this decade. The evolving paradigm of technology use, the deep learning of computer skills that students will require for future employment and how this can be incorporated into appropriate pedagogies for gifted learners also poses challenges for teachers. This thesis reports on a unique mentoring program that was developed to utilise desktop videoconferencing (DVC) technology and designed to specifically address these challenges. The study was undertaken in a large independent school (K-12) in New South Wales, Australia and involved six students and six teachers, none of whom had any previous experience of DVC or mentoring. The aim of the study was to investigate learning outcomes for teachers and gifted students. This study employed DVC as a didactic strategy over a 10-week period. The mentoring sessions of the cohorts and their post-mentoring interviews were evaluated using grounded theory methods of data gathering and analysis over a 2-year period. The findings demonstrated that the nature of learning during DVC could be constructed as an emergent theory, based on the teaching philosophies of the teachers and their goals for their students. Technical support, relational mentors and motivational tasks created supportive environments for DVC. Perseverance, enthusiasm and resilience enhanced the uniqueness of mentoring program. Several recommendations are also posited for further research.
4

INVESTIGATION OF TRAFFIC CRASHES IN TWO-LANE RURAL HIGHWAYS IN OHIO

Alhomidan, Abdullah January 2006 (has links)
No description available.
5

Etude de la dynamique des Escherichia coli dans les rivières du bassin de la Seine

Garcia Armisen, Tamara 15 February 2006 (has links)
The purpose of our study was to describe the dynamics of E. coli in the rivers of the Seine watershed. This watershed is characterized by a poor microbiological water quality due to an important population density, industrial activities and intensive agriculture. The main objectives of our study were to obtain field microbiological data describing the system and to understand the underlying mechanisms in order to build a model able to describe and predict the fate of the fecal bacteria at the scale of the whole watershed. This model was built in order to help management of microbiological water quality. To be able to describe and modelize the fate of fecal bacteria at the scale of such a large and complex system, it was first necessary to identify and quantify the sources of contamination and to be able to describe the processes affecting these bacteria once discharged to the rivers. The quantification of E. coli in the natural aquatic systems through the traditional culture-based techniques has been strongly questioned during the last years because they have a long response delay (24 to 48 h) and they do not take into account the viable but not culturable bacteria (VBNC) which nevertheless could represent a health thread. For this reason we developed in this study two alternative methods: the direct (without passing through a cultivation step) measurement of the â-D-glucuronidase activity and a fluorescent in situ hybridization with an E. coli specific probe coupled with a viability test. The first has the main advangate to give a very rapid evaluation of the E. coli content of the water while the second one was able to enumerate VBNC E. coli. The study of the sources of contamination of the rivers revealed the predominance, in this anthropogenicised watershed, of the point sources (effluents from wastewater tretament plants). Diffuse sources soil leaching and surface runoff) may nevertheless be locally important and have also be quantified. The influence of the land use on these diffuse sources has been quantified demonstrating that soil leaching and surface runoff of grazed areas was mainly responsible of fecal contamination in rural areas. The attachment of E .coli to particles in the river waters was studied as it can influence the fate of this kind of bacteria in the aquatic systems. A linear regression was found between the percentage of particle-associated E. coli and the SM content of the water. Settling velocities of particle-associated E. coli were determined. The mortality rate of E. coli was analysed following various perspectives: the river order, the attachment of E. coli to particles, the importance of the cultivability loss in the disappearance of these bacteria and the importance of protozoan grazing. The results confirmed the importance of grazing and showed that the abondance of free living E. coli bacteria decreased two times more rapidly than particle-associated E. coli. In the Seine river, we showed that the net loss of culturable E. coli was 1.5 time higher than the net loss of viable E. coli. Finally, no relationship was found between mortality rate and river order. These results have been used to build two models CF-SENEQUE and CF-SiAM-3D which describe E. coli dynamics respectively for the whole Seine river watershed and for the Seine for the estuary. Comparisons model calcultaions with field data of fecal coliforms abundances showed that these models correctly simulated the longitudinal distribution of fecal colifoms in the main rivers of the Seine watershed and in the estuary. These models were used to test the impact on the microbiological water quality of various scenarii of wastewater management .
6

DDM: Study of deer detection and movement using deep learning techniques

Siddique, Md Jawad 01 December 2021 (has links)
Deer Vehicle Collisions (DVCs) are a global problem that is not only resulting in seriousinjuries to humans but also results in loss of human and deer lives. Deer are more active and less attentive during the mating and hunting seasons. Roadside deer activity such as feeding and strolling along the roadside has a significant correlation with DVCs. To mitigate DVCs, several strategies were used that include vegetation management, fences, underpasses and overpasses, population reduction, warning signs and animal detection systems (ADS). These strategies vary in their efficacy. These strategies may help to reduce DVCs. However, they are not always easily feasible due to false alarms, high cost, unsuitable terrain, land ownership, and other factors. Thus, DVCs are increasing due to the increase in number of vehicles and the absence of intelligent highway safety and alert systems. Detecting deer in real-time on our roads is a challenging problem. Thus, this research work proposed a deer detection and movement DDM technique to automate DVCs mitigation system. The DDM combines computer vision, artificial intelligent methods with deep learning techniques. DDM includes two main deep learning algorithms 1)onestage deep learning algorithm based on Yolov5 that generates a detection model(DM) to detect deer and 2) deep learning algorithm developed by python toolkit DeepLabCut to generate movement model(MM) for detecting the movement of the deer. The proposed method can detect deer with 99.7% precision and succeeds to ascertain if the deer is moving or static with an inference speed of 0.29s. The proposed method can detect deer with 99.7% precision and using DeepLabCut toolkit on the detected deer we can ascertain if the deer is moving or static with an inference speed of 0.29s.
7

Estudio del papel de las amebas de vida libre como reservorio de Helicobacter pylori y otras bacterias patógenas en aguas y alimentos mediante técnicas moleculares

Moreno Mesonero, Laura 05 November 2018 (has links)
En esta Tesis se estudia el posible papel de las FLA como reservorio de H. pylori y otras bacterias patógenas en aguas y alimentos mediante técnicas moleculares. En primer lugar se realizó un ensayo de cocultivo entre la bacteria H. pylori y la ameba Acanthamoeba castellanii. Se comprobó, mediante técnicas moleculares específicas para la detección de células viables, PMA-qPCR y DVC-FISH, que la ameba es capaz de internalizar a la bacteria y que esta última permanece viable, demostrando que H. pylori se comporta como una bacteria ARB. Seguidamente, se analizaron un total de 120 muestras ambientales, 100 de agua y 20 de vegetales para comprobar la presencia, tanto de FLA como de H. pylori internalizado en estas FLA. En el caso de las muestras de agua, se analizaron 69 muestras de agua residual y 31 de agua potable. Un total de 55 (79,7%) muestras de agua residual y 12 (38,7%) de agua potable resultaron positivas para la presencia de FLA. Mediante la técnica PMA-qPCR se demostró la presencia de H. pylori internalizado en las FLA presentes en 28 (50,9%) y 11 (91,7%) de las muestras de agua residual y potable analizadas, respectivamente. Mediante DVC-FISH se demostró que las células de H. pylori internalizadas dentro de las FLA presentes en las muestras eran viables en 16 (29,5%) y 5 (41,7%) de las muestras de agua residual y potable analizadas, respectivamente. Además, se consiguió recuperar formas viables cultivables de H. pylori procedente del interior de FLA en 10 (18,2%) de las muestras de agua residual analizadas. Las FLA aisladas e identificadas en las aguas residuales pertenecieron a los géneros Acanthamoeba, Naegleria, Vanellidae y a la familia Vahlkampfiidae. En el caso del agua potable, las FLA aisladas e identificadas pertenecieron a los géneros Acanthamoeba, Echinamoeba y Vermamoeba. En el caso de las muestras de vegetales, concretamente lechugas, todas ellas resultaron positivas para el aislamiento de FLA (100%). Mediante la técnica PMA-qPCR se demostró la presencia de H. pylori internalizado en las FLA en 11 (55,0%) de las muestras y, mediante DVC-FISH, se demostró que las células de H. pylori internalizadas dentro de las FLA eran viables en 5 (25,0%) de las muestras. En este caso no se recuperaron formas viables cultivables de la bacteria. Finalmente, mediante metagenómica de secuenciación dirigida, se analizó el microbioma de las FLA presentes en 20 de las muestras analizadas en esta Tesis (11 de agua residual, 3 de agua potable y 6 de lechugas). Para ello, se eligieron los iniciadores, se evaluaron in silico e in vitro y, una vez comprobada su idoneidad, se emplearon para la secuenciación de las muestras. En los tres tipos de muestras, la clase bacteriana más abundante fue la Gammaproteobacteria. Para los tres tipos de muestras, los filos más abundantes de las bacterias del microbioma de las FLA fueron Proteobacteria y Bacteroidetes y, en el caso del agua residual, también lo fue el filo Planctomycetes. H. pylori se detectó mediante esta técnica en los tres tipos de muestra. Además, como parte del microbioma de FLA de muestras ambientales, se detectaron otras bacterias de interés para la salud pública, tales como Aeromonas, Legionella, Mycobaterium o Pseudomonas. Los resultados obtenidos en esta Tesis demuestran la presencia de FLA patógenas en las muestras ambientales, así como el hecho de que, en algunos casos, estas son transportadoras de bacterias patógenas. Este trabajo también confirma que H. pylori se comporta como una bacteria ARB y que se encuentra viable en el interior de FLA presentes, tanto en aguas residuales y potables como en vegetales. De esta forma, se postula que un modo de transmisión de esta bacteria podría ser a través de las FLA presentes en agua o vegetales. / In this Thesis, the possible role of FLA is studied as a reservoir of H. pylori and other pathogenic bacteria in waters and food by means of molecular techniques. Firstly, a coculture assay between the bacterium H. pylori and the amoeba Acanthamoeba castellanii was carried out. It was verified by means of molecular techniques specific for the detection of viable cells, PMA-qPCR and DVC-FISH, that the amoeba is capable of internalizing the bacterium and that the latter remains viable, demonstrating that H. pylori behaves as an ARB bacterium. Afterwards, a total of 120 environmental samples, 100 of water and 20 of vegetables, were analyzed to verify the presence FLA as well as internalized H. pylori into these FLA. In case of water samples, 69 samples of wastewater and 31 samples of drinking water were analyzed. A total of 55 (79,7 %) wastewater and 12 (38,7 %) of drinking water samples turned out to be positive for FLA's presence. By means of PMA-qPCR technique, the presence of FLA-internalized H. pylori was demonstrated in 28 (50,9 %) and 11 (91,7 %) of the wastewater and drinking water samples analyzed, respectively. By means of DVC-FISH it was demonstrated that the FLA-internalized H. pylori cells were viable in 16 (29,5 %) and 5 (41,7 %) of the wastewater and drinking water samples analyzed, respectively. In addition, viable cultivable forms of H. pylori coming from the inside of FLA were recovered from 10 (18,2 %) of the analyzed wastewater samples. The isolated and identified FLA from wastewater samples belonged to the genus Acanthamoeba, Naegleria, Vanellidae and to the family Vahlkampfiidae. In the case of drinking wáter, the isolated and identified FLA belonged to the genus Acanthamoeba, Echinamoeba and Vermamoeba. In the case of the vegetable samples, specifically lettuces, all of them turned out to be positive for FLA's isolation (100 %). By means of the PMA-qPCR technique, the presence of FLA-internalized H. pylori was demonstrated in 11 (55,0 %) of the samples and, by means of DVC-FISH, it was demonstrated that FLA-internalized H. pylori cells were viable in 5 (25,0 %) of the samples. In this case, viable cultivable forms of the bacterium could not be recovered. Finally, by means of amplicon-based metagenomics, the FLA microbiome of 20 previously analyzed samples in this Thesis (11 wastewater, 3 drinking water and 6 lettuce samples) was analyzed. To do so, a pair of primers were selected and evaluated in silco and in vitro and, once checked its suitability, they were used to perform the samples' sequencing. In the three types of samples, the most abundant bacterial class was the Gammaproteobacteria. For the three types of samples, the most abundant bacterial phylum of the FLA microbiome were Proteobacteria and Bacteroidetes and, in case of the wastewater, it was also the phylum Planctomycetes. H. pylori was detected by means of this technology in the three types of samples. In addition, as part of FLA's microbiome of environmental samples, other bacteria of public health interest were detected, such as Aeromonas, Legionella, Mycobacterium or Pseudomonas. The results obtained in this Thesis demonstrate the presence of pathogenic FLA in the environmental samples, as well as the fact that, in some cases, these they are carriers of pathogenic bacteria. This work also confirms that H. pylori behaves as an ARB bacterium and that it is viable inside the present FLA in wastewater as well as in drinking water and in vegetables. This way, it is postulated that a way of transmission of this bacterium might be through the FLA present in water or vegetables. / En esta Tesi s'estudia el possible paper de les FLA com a reservori de H. pylori i altres bacteris patògens en aigües i aliments per mitjà de tècniques moleculars. En primer lloc es va realitzar un assaig de cocultiu entre el bacteri H. pylori i l'ameba Acanthamoeba castellanii. Es va comprovar per mitjà de tècniques moleculars específiques per a la detecció de cèl¿lules viables, PMA-qPCR i DVC-FISH, que l'ameba és capaç d'internalizar al bacteri i que esta última roman viable, demostrant que H. pylori es comporta com un bacteri ARB. A continuació, es van analitzar un total de 120 mostres ambientals, 100 d'aigua i 20 de vegetals per a comprovar la presència tant de FLA com de H. pylori internalitzat en estes FLA. En el cas de les mostres d'aigua, es van analitzar 69 mostres d'aigua residual i 31 d'aigua potable. Un total de 55 (79,7%) mostres d'aigua residual i 12 (38,7%) d'aigua potable van resultar positives per a la presència de FLA. Per mitjà de la tècnica PMA-qPCR es va demostrar la presència d'H. pylori internalitzat en les FLA presents en 28 (50,9%) i 11 (91,7%) de les mostres d'aigua residual i potable analitzades, respectivament. Per mitjà de DVC-FISH es va demostrar que les cèl¿lules d'H. pylori internalitzades dins les FLA presents en les mostres eren viables en 16 (29,5%) i 5 (41,7%) de les mostres d'aigua residual i potable analitzades, respectivament. A més, es va aconseguir recuperar formes viables cultivables d'H. pylori procedent de l'interior de FLA en 10 (18,2%) de les mostres d'aigua residual analitzades. Les FLA aïllades i identificades en les aigües residuals van pertànyer als gèneres Acanthamoeba, Naegleria, Vanellidae i a la família Vahlkampfiidae. En el cas de l'aigua potable, les FLA aïllades i identificades van pertànyer als gèneres Acanthamoeba, Echinamoeba i Vermamoeba. En el cas de les mostres de vegetals, concretament encisams, totes elles van resultar positives per a l'aïllament de FLA (100%). Per mitjà de la tècnica PMA-qPCR es va demostrar la presència d'H. pylori internalitzat en les FLA en 11 (55,0%) de les mostres i, per mitjà de DVC-FISH, es va demostrar que les cèl¿lules d'H. pylori internalitzades dins les FLA eren viables en 5 (25,0%) de les mostres. En este cas no es van recuperar formes viables cultivables del bacteri. Finalment, per mitjà de metagenómica de seqüenciació dirigida, es va analitzar el microbioma de les FLA presents en 20 de les mostres analitzades en esta Tesi (11 d'aigua residual, 3 d'aigua potable i 6 d'encisams). Per tal de fer això, es van triar els iniciadors, es van avaluar in silico i in vitro i, una vegada comprovada la seua idoneïtat, es van emprar per a la seqüenciació de les mostres. En els tres tipus de mostres, la classe bacteriana més abundant va ser la Gammaproteobacteria. Per als tres tipus de mostres, els filos més abundants dels bacteris del microbioma de les FLA van ser Proteobacteria i Bacteroidetes i, en el cas de l'aigua residual, també ho va ser el filo Planctomycetes. H. pylori es va detectar per mitjà d'esta tècnica en els tres tipus de mostra. A més, com a part del microbioma de FLA de mostres ambientals, es van detectar altres bacteris d'interés per a la salut pública, com ara Aeromonas, Legionella, Mycobaterium o Pseudomonas. Els resultats obtinguts en esta Tesi demostren la presència de FLA patògenes en les mostres ambientals, així com el fet de que, en alguns casos, estes són transportadores de bacteris patògens. Este treball també confirma que H. pylori es comporta com un bacteri ARB i que es troba viable en l'interior de FLA presents, tant en aigües residuals i potables com en vegetals. D'esta manera, es postula que una manera de transmissió d'este bacteri podria ser a través de les FLA presents en aigua o vegetals. / Moreno Mesonero, L. (2018). Estudio del papel de las amebas de vida libre como reservorio de Helicobacter pylori y otras bacterias patógenas en aguas y alimentos mediante técnicas moleculares [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/111952
8

Mise en oeuvre de la méthode des éléments naturels contrainte en 3D : application au cisaillage adiabatique

Illoul, Amran Lounès 09 July 2008 (has links) (PDF)
Ce travail porte sur la mise en oeuvre en 3d de la méthode des éléments naturels contrainte CNEM en vue de son utilisation pour la simulation du cisaillage à grande vitesse. La CNEM est une approche à mi-chemin des approches sans maillage et des éléments finis. La construction de son interpolation utilise le diagramme de Voronoï contraint (dual du maillage de Delaunay contraint) associé à un nuage de noeud réparti sur le domaine étudié muni d'une description de sa frontière. La mise en oeuvre de la CNEM comporte trois aspects principaux : i) la construction du diagramme de Voronoï contraint, ii) le calcul des fonctions de forme éléments naturels Sibson, iii) la discrétisation d'une formulation variationnelle générique par utilisation de l'intégration nodale stabilisée conforme, SCNI, introduite par Chen et Al en 2001. Une partie importante de ce travail concerne les deux derniers points. Pour le calcul des fonctions de formes Sibson 3d cinq algorithmes sont présentés, dont deux développés au cours de la thèse, et sont comparés en terme de performance. Par ailleurs, une discrétisation est proposée pour être applicable au cas des domaines fortement non convexes. La mise en oeuvre proposée est validée sur des exemples en élasticité linéaire 3d en petites perturbations (vis à vis de solutions analytiques et de résultats éléments finis) puis en grandes transformations (test de la barre de Taylor). L'application de la CNEM au cisaillage grande vitesse est finalement abordée. Les développements effectués ont été intégrés à la plateforme logicielle Nessy. Cette plateforme a pour objectif la capitalisation du savoir faire du LMSP en simulation numérique.
9

An Empirical Study on AI Workflow Automation for Positioning / En empirisk undersökning om automatiserat arbetsflöde inom AI för positionering

Jämtner, Hannes, Brynielsson, Stefan January 2022 (has links)
The maturing capabilities of Artificial Intelligence (AI) and Machine Learning (ML) have resulted in increased attention in research and development on adopting AI and ML in 5G and future networks. With the increased maturity, the usage of AI/ML models in production is becoming more widespread, and maintaining these systems is more complex and likely to incur technical debt when compared to standard software. This is due to inheriting all the complexities of traditional software in addition to ML-specific ones. To handle these complexities the field of ML Operations (MLOps) has emerged. The goal of MLOps is to extend DevOps to AI/ML and therefore speed up development and ease maintenance of AI/ML-based software, by, for example, supporting automatic deployment, monitoring, and continuous re-training of models. This thesis investigates how to construct an MLOps workflow by selecting a number of tools and using these to implement a workflow. Additionally, different approaches for triggering re-training are implemented and evaluated, resulting in a comparison of the triggers with regards to execution time, memory and CPU consumption, and the average performance of the Machine learning model.
10

Etude de la dynamique des Escherichia coli dans les rivières du bassin de la Seine

Garcia Armisen, Tamara 15 February 2006 (has links)
The purpose of our study was to describe the dynamics of E. coli in the rivers of the Seine watershed. This watershed is characterized by a poor microbiological water quality due to an important population density, industrial activities and intensive agriculture. The main objectives of our study were to obtain field microbiological data describing the system and to understand the underlying mechanisms in order to build a model able to describe and predict the fate of the fecal bacteria at the scale of the whole watershed. This model was built in order to help management of microbiological water quality. <p>To be able to describe and modelize the fate of fecal bacteria at the scale of such a large and complex system, it was first necessary to identify and quantify the sources of contamination and to be able to describe the processes affecting these bacteria once discharged to the rivers. <p>The quantification of E. coli in the natural aquatic systems through the traditional culture-based techniques has been strongly questioned during the last years because they have a long response delay (24 to 48 h) and they do not take into account the viable but not culturable bacteria (VBNC) which nevertheless could represent a health thread. For this reason we developed in this study two alternative methods: the direct (without passing through a cultivation step) measurement of the â-D-glucuronidase activity and a fluorescent in situ hybridization with an E. coli specific probe coupled with a viability test. The first has the main advangate to give a very rapid evaluation of the E. coli content of the water while the second one was able to enumerate VBNC E. coli. <p>The study of the sources of contamination of the rivers revealed the predominance, in this anthropogenicised watershed, of the point sources (effluents from wastewater tretament plants). Diffuse sources soil leaching and surface runoff) may nevertheless be locally important and have also be quantified. The influence of the land use on these diffuse sources has been quantified demonstrating that soil leaching and surface runoff of grazed areas was mainly responsible of fecal contamination in rural areas.<p>The attachment of E .coli to particles in the river waters was studied as it can influence the fate of this kind of bacteria in the aquatic systems. A linear regression was found between the percentage of particle-associated E. coli and the SM content of the water. Settling velocities of particle-associated E. coli were determined. The mortality rate of E. coli was analysed following various perspectives: the river order, the attachment of E. coli to particles, the importance of the cultivability loss in the disappearance of these bacteria and the importance of protozoan grazing. The results confirmed the importance of grazing and showed that the abondance of free living E. coli bacteria decreased two times more rapidly than particle-associated E. coli. In the Seine river, we showed that the net loss of culturable E. coli was 1.5 time higher than the net loss of viable E. coli. Finally, no relationship was found between mortality rate and river order. <p>These results have been used to build two models CF-SENEQUE and CF-SiAM-3D which describe E. coli dynamics respectively for the whole Seine river watershed and for the Seine for the estuary. Comparisons model calcultaions with field data of fecal coliforms abundances showed that these models correctly simulated the longitudinal distribution of fecal colifoms in the main rivers of the Seine watershed and in the estuary. These models were used to test the impact on the microbiological water quality of various scenarii of wastewater management .<p> / Doctorat en sciences, Spécialisation biologie animale / info:eu-repo/semantics/nonPublished

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