Les interactions entre les eaux souterraines et les eaux de surface sont complexes et jouent un rôle prépondérant dans le fonctionnement des hydrosystèmes, tant en termes quantitatifs que qualitatifs. Ces deux compartiments interagissent à travers différentes interfaces emboitées depuis l’échelle locale, notamment la zone d’interface rivière-nappe, appelée zone hyporhéique (ZH) jusqu’à l’échelle régionale. La ZH se définit comme un buffer entre les eaux souterraines et les eaux de surface. Les variations des flux d’eau et de chaleur au niveau de cette zone modulent les processus biogéochimiques. Le but de cette thèse est d’améliorer la compréhension du régime thermique et hydrologique de la ZH et de sa variation spatiale. Cette problématique est abordée par l’utilisation de stations de mesures haute fréquence des échanges nappe-rivière (MOLONARI) sur le bassin des Avenelles (sous bassin de la Seine (46 km2)) et de la modélisation. Le suivi haute fréquence a permis de réaliser une analyse des données expérimentales présentant le régime hydro-climatique du bassin ainsi que l’évolution spatiale et temporelle du fonctionnement des différents compartiments de l’hydrosystème. Un cas synthétique a été réalisé afin de caractériser les différents facteurs contrôlant le régime thermique de l’interface nappe rivière et la variation de stocks d’énergie au sein de la ZH. La démarche de modélisation suivie pour le cas synthétique fournit un cadre d’analyse des données des cinq stations MOLONARI. Les données acquises sur ces stations ont été utilisées afin de déterminer les propriétés hydrodynamiques et thermiques de la ZH ainsi que des couches géologiques sous-jacentes par inversion à l’aide du modèle METIS couplé à un script de balayage de l’espace des paramètres afin de quantifier les flux d’eau et de chaleur à l’interface nappe-rivière le long d'un corridor hydraulique. Les résultats du modèle mettent en lumière la variabilité spatio-temporelle des échanges de chaleur au niveau des cinq stations MOLONARI. La quantification des flux de chaleur a fourni un nouvel éclairage des interactions entre les eaux de surface et les eaux souterraines à l’interface nappe-rivière du bassin des Avenelles. / The river-aquifer interactions are complex and play a preponderant role in hydrosystems functioning, in both qualitative and quantitative terms. These two compartments interact through various nested interfaces from the local scale in particular the river aquifer interface called the Hyporheic Zone (HZ) to the regional scale. The HZ acts as a buffer between the stream and the groundwater. The water and heat fluxes variation at this zone modulates the biogeochemical processes.The aim of this thesis, is to improve the understanding of the thermal and hydrological regime of the HZ and its spatial variation. This problem is approached by the use of high frequency measurement stations of river-aquifer exchanges (LOMOS) in the Avenelles basin (sub-basin of the Seine basin (46 km2)) and by modeling. The high frequency monitoring allowed to realize an analysis of the experimental data characterizing the hydroclimatic regime of the Avenelles basin as well as the spatial and temporal evolution of the hydrosystem various compartments functioning.A synthetic case was realized to characterize the main factors controlling the thermal regime at the river aquifer interface and the energy storage variation within the ZH. The modeling approach followed by the synthetic case provides an analysis framework of the five LOMOS data.The acquired LOMOS data were used to determine the hydrogeological and thermal properties of the HZ and of the underlying aquifers by inversion by means of a 2D finite element thermo-hydrogeological model (METIS) coupled with a parameters screening script to quantify water and heat fluxes through the stream – aquifer interface over along the stream network.The model results highlight the spatiotemporal variability of the heat exchanges at the five LOMOS. The quantification of heat fluxes provided a new lighting of the stream-aquifer interactions of the Avenelles basin.

Constituée de cinq chapitres, cette thèse s'intéresse aux mécanismes d'ajustement macroéconomique dans une union monétaire telle que la zone euro. Le premier chapitre examine la réponse de la mobilité du travail aux disparités entre les taux de croissance des salaires et les taux de chômage dans la zone euro. Les résultats indiquent que la mobilité répond aux différences nationales en matière de chômage, en particulier pendant la période de crise récente, mais pas aux différences nationales dans l'évolution des salaires. Le deuxième chapitre étudie l'effet d'équilibre ou de déséquilibre de la mobilité du travail sur les conditions du marché du travail dans la zone euro. Les résultats montrent que même si la mobilité réagit faiblement aux chocs asymétriques et aux caractéristiques structurelles dans la zone euro, elle réduit les écarts dans les conditions du marché du travail. Le troisième chapitre analyse les déterminants de la migration dans la zone euro par rapport à l'Union européenne (UE). L'objectif principal est d'identifier les facteurs qui entravent la mobilité des personnes dans la zone euro. Les principaux résultats indiquent que, mis à part les obstacles culturels et administratifs, un système de sécurité sociale généreux dans le pays d'origine freine également la mobilité des personnes dans la zone euro. Le quatrième chapitre examine le rôle stabilisateur des envois de fonds des travailleurs comme retombées de la mobilité des personnes. Les résultats montrent que les envois de fonds ne jouent pas un rôle stabilisateur ni dans la zone euro ni dans l'UE. Pire encore, les envois de fonds des travailleurs ont tendance à être procycliques dans l'UE. Enfin, le cinquième chapitre s'intéresse au partage des risques dans l’UE et met en évidence le poids des flux de revenus du travail dans le lissage des chocs asymétriques. Les résultats révèlent que le canal de partage des risques le plus important reste le marché du crédit. Le canal du marché des capitaux est quant à lui procyclique. En ce qui concerne les flux de revenus du travail, leur effet de lissage existe mais il est faible. / This thesis consists of five essays on macroeconomic adjustment mechanisms in a currency union such as the Euro area. The first essay examines the response of labour mobility to disparities in wage growth and unemployment rate in the Euro area. The results indicate that mobility responds to national differences in unemployment, especially during the crisis period, but not to national differences in wage developments. The second essay investigates the equilibrium or disequilibrium effect of labour mobility on labour market conditions in the Euro area. The findings show that even if mobility responds weakly to asymmetric shocks and structural patterns in the Euro area, it reduces differentials on labour market conditions. The third essay analyses the determinants of migration in the Euro area in comparison with the European union (EU) ; the main purpose being to identify factors that hinder mobility of people in the Euro area. The main results indicate that apart from cultural and administrative barriers, a generous social security system in the country of origin is also a drag to mobility of people in the Euro area. The fourth essay examines the stabilising role of workers' remittances as a spillover effect of labour mobility. The results show that remittances do not play a stabilising role neither in the Euro area, nor in the EU. Worse still, workers' remittances tend to be procyclical in the EU. Finally, the fifth essay looks at the risk sharing in the EU and highlights the weight of labour income flows in smoothing asymmetric shocks. The outcomes reveal that the most important channel of risk sharing remains the credit market. As for the capital market channel, it tends to be procyclical. Regarding labour income flows, their smoothing effect exists but it is low.

As an important technique for corrosion control in marine environment, Cathodic Protection (CP) should be applied with a full understanding of environmental conditions and a good consideration of current requirements. Early studies on different kinds of steel specimens in the intertidal zone show severe corrosion losses. Nevertheless, there is evidence that CP can work in these regions of a steel structure because electrolyte pathway can remain some time on thin wetted surfaces when tides recede. This research aims to study corrosion activities and their behaviour under the influence of CP in a thin layer of electrolyte as a simulation of the inter-tidal zone. By means of a mechanical vibrating probe, Scanning Vibrating Electrode Technique (SVET) may be used to study local activities at coating defects in a thin electrolyte layer. The effect of CP on the local currents at the defect site was confirmed by SVET and, significantly, the development of calcareous films under these conditions in seawater was also observed. Such films are found to be effective in the absence of cathodic polarisation and only failed after damage. In order to explore the performance of applying CP, a Finite Element (FE) model of electrically connected zinc and steel samples beneath a specific thickness of electrolyte has been created, with full polarisation curves implemented for each metal based on experimental results obtained. The influence of the electrolyte conductivity and the geometry of the electrodes has also been considered. A comparison can then be made between experimental investigation and computational modelling of this corrosion cell. Epoxy-coated and uncoated mild steel samples obtained in the simulated tidal facility were also investigated. The formation of calcareous films was confirmed. Calcareous films were protective under these intermittent wetting conditions. Techniques used to understand the performance include optical observation, Scanning Electron Microscopy (SEM) together with Energy Dispersive X-ray (EDX) and X-ray Diffraction (XRD) analysis.

Work zones present a risk to drivers and to personnel constructing the roadway. In 2005 work zones accounted for 2.5% of fatalities nationwide, 3.5% for the state of Utah. The goal of this research is to make work zones safer by quantifying the risk that they present to drivers. The approach of this research has been to review part 6 of the Manual of Uniform Traffic Control Devices (MUTCD) and compare the differences from the 2003 and 2009 editions, conduct field studies of Utah work zones, and develop a tool for measuring risk in work zones. In the 2009 MUTCD an effort is made to provide additional safety measures to disabled pedestrians. Also, guidelines are set for the use of new technology for work zones, flagger procedures, and incident management. Research was done to ascertain what several states are doing to promote safety around work zones. The states that are highlighted in this report are Arkansas, North Carolina, Illinois, Pennsylvania, New Mexico, Minnesota, and Virginia. These methods include integration of a Smart Work Zone system, late lane merge, investigation of higher quality traffic control devices, and application of other technologies to make drivers aware of work zone conditions. Discussion about the various technologies available and their effects on traffic found through research is also provided in this thesis. Research for safety and safety regulations continues. An audit process developed at Utah State University and the Illinois Institute of Technology was used to conduct an evaluation of work zones in Utah. The audit was instrumental in evaluating the measures being used on highway and interstate roads work sites. The results and observations of this research were utilized to make standards concerning conditions of signs and delineation devices. Also observations were used to determine risk factors pertaining to a work zone. These factors were implemented in a spreadsheet that served as an analysis tool for quantification of risk in a work zone. Eleven projects in highways and arterials were audited and analyzed with the analysis tool developed. The risk scores attained from this tool range in value, and though the values may not be an exact value of the present risk, the tool still proved to be effective as an estimation device for auditors and contractors alike. The tool also proved efficient in quickly identifying the areas of concern in the work zone, and giving an estimate on the impact that improvements will have on the safety of workers and drivers. For the 11 work zones audited, the recommendations were enforcement of speed limit, improvement of signs in the work zone, and use of positive protection, among others.

For Maori, the management fo New Zealand�s coast and its resources is fundamental to their cultural identity. Iwi and hapu throughout New Zealand have close relationships with the coast and unique rights and responsibilities for its future management. However, there does not appear to be wide recognition of the crucial role of Maori in New Zealand�s coastal management regime. Co-management initiatives in coastal management, particularly under the Conservation Act 1987, Resource Management Act 1991 and several legislative initiatives controlling fisheries management, are explored and critiqued. Overall, the initiatives demonstrate that progress is being made in coastal management for better protection of Maori coastal values. Nevertheless, there is scope for further improvements concerning greater Maori involvement in coastal management. Recommendations for genuine co-management systems in New Zealand�s coastal management regime include effective communication between iwi and Government; appreciation of the unique nature of each iwi in New Zealand; involvement of a third party communicating between iwi and Government representatives; appropriate funding and resources to maintain the co-management system, and encouragement and motivation from the Government to initiate and maintain the co-management system.

<p>Many studies on neurogenesis in adult dentate gyrus (DG) have been performed on rodents and other mammalian species, but only a few on adult human DG.  This study is focusing on neurogenesis in adult human DG. To characterize the birth of cells in DG, the expression of the cell proliferation marker Ki67 was examined using immunohistochemistry. Ki67-positive labelling was indeed observed in the granular cell layer and the molecular layer of dentate gyrus and in the hilus of hippocampus, as well as in the subgranular zone (SGZ). The Ki67 positive nuclei could be divided into three groups, based on their morphology and position, suggesting that one of the groups represents neuronal precursors. Fewer Ki67 positive cells were seen in aged subjects and in subjects with an alcohol abuse. When comparing the Ki67 positive cells and the amount of blood vessels as determined by anti factor VIII, no systematic pattern could be discerned. To identify possible stem/progenitor cells in DG a co-labelling with nestin and glial fibrillary acid protein was carried out. Co-labelling was found in the SGZ, but most of the filaments were positive for just one of the two antibodies. Antibodies to detect immature/mature neurons were also used to investigate adult human neurogenesis in DG. The immature marker βIII-tubulin showed a weak expression. The other two immature markers (PSA-NCAM and DCX) used did not work, probably since they were not cross-reacting against human tissue. In summary, this study shows that new cells are continuously formed in the adult human hippocampus, but at a slower pace compared to the rat, and that some of these new cells may represent neuronal precursors.</p>

The impact of the soil structure on flow and transport in partially water saturated soils is currently still a matter of scientific debate. The major aim of this thesis was to investigate the relation between heterogeneity and transport for a natural unsaturated heterogeneous Tertiary sand deposit. In the first part, we analyzed the flow and transport at the scale of an undisturbed monolith. Chloride breakthrough curve experiments were used to derive an apparent dispersion coefficient at the TDR sampling and monolith scale. Application of a Brilliant Blue pulse allowed further the visualization of flow distribution within the monolith. Small undisturbed soil cores were sampled throughout the monolith and the hydraulic characteristic curves at the scale of the cores were determined. Textural variability and structure as inferred from the inspection of the Brilliant Blue pattern and analysis of the small core sampling were subsequently implemented in a 3-D model and transport was simulated. The simulations clearly revealed the importance of the macro-structure on the transport behavior of the soil. We also showed that the micro-variability heterogeneity component was needed to assess the scaling of the effective and local scale dispersivity. In the second part, we studied in-situ chloride transport in the vadose formation separating the bottom of a lake and an unconfined aquifer. First the uncertainty generated by the undersampling of the lake chloride concentration time series were investigated. Subsequently, velocity and dispersivity profiles were assessed by inverse modeling of the soil chloride concentration time series. We observed that the clay layers induced an increase of the dispersivity below them. We hypothesize that fingering flow or convergence phenomena, occurring below sand-clay interfaces, lead to non-representative artificially high dispersivity values. Velocity and dispersivity values just above the clay layers however seem more reliable due to convergence phenomena and better lateral mixing induced by a larger water content. In this formation, the transport behavior could be characterized considering a hierarchical structure of the subsoil heterogeneity. In this model, the flow field micro-variability is influenced by pore structure (possibly characterized by scaling factors). The next complexity level is induced by the slight layering resulting from the sedimentation process (not investigated in this work). Then, the third hierarchical level is assessed by the macro-structure and the sequence of clay layers in the sand. Each of these levels is assumed to have an effect on the solute mixing process and effective macro-dispersivity.

The purpose of this study was to determine the effects of participation in Read 180, a teacher-mediated, computer-mediated reading instruction program, on the reading proficiency of 4th and 5th grade English Language Learners. The students who participated in the Read 180 program scored below the 25th percentile on the Florida Comprehensive Assessment Test (FCAT). Cultural-historical activity theory guided the research. Research questions for the study were answered with quantitative and qualitative methods. The questions asked were: 1. What are the effects of participation in Read 180, a teacher-mediated computer-mediated-integrated learning system that provides reading instruction, on the growth in reading proficiency of a group of participating English Language Learners? 2. What are the effects of participation in Read 180, a teacher-mediated computer-mediated integrated learning system that provides reading instruction, on the reading achievement of a group of participating English Language Learners when compared with the reading achievement of a group of English Language Learners with similar characteristics receiving reading instruction supported by a reading basal program? 3. How does the mediated structure of Read 180, a teacher-mediated, computer-mediated integrated learning activity system that provides reading instruction and surrounding activity systems interact to affect learning? Data analysis revealed that the fourth and fifth grade experimental group significantly improved their proficiency on the Scholastic Reading Inventory. Analysis of pre- and post-test scores obtained with the Florida Comprehensive Assessment (FCAT) of fourth and fifth grade experimental and control groups were not statistically significant. Qualitative findings indicated that the organization of classroom instruction had a significant impact on the quality of instruction. A discussion of the findings presents several implications and recommendations for future research on teacher-mediated, computer-mediated reading instruction.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 28, 2007) Vita. Includes bibliographical references.

A multiple scale theory is developed for the prediction of damage evolution in heterogeneous viscoelastic media. Asymptotic expansions of the field variables are used to derive a global scale viscoelastic constitutive equation that includes the effects of local scale damage. Damage, in the form discrete cracks, is allowed to grow according to a micromechanically-based viscoelastic traction-displacement law. Finite element formulations have been developed for both the global and local scale problems. These formulations have been implemented into a two-scale computational model Numerical results are given for several example problems in order to demonstrate the effectiveness of the technique.