Dengue fever is a debilitating, viral, mosquito-borne disease occurring in tropical and subtropical areas in the world. The majority of dengue cases in the United States were acquired in endemic areas by travelers or immigrants. However, in recent years, autochthonous (locally acquired) dengue cases have been diagnosed in Florida. The purpose of this study was to find an association between potential risk factors and the expansion of dengue fever in the United States. Guided by the eco-bio-social framework, which offers a broad assessment of risk factors for the illness, a retrospective design was used with archival data to correlate changes in climatic variables and imported dengue cases with autochthonous dengue cases in Southeast Florida from 1980 to 2013. A Spearman correlation indicated weak correlations between temperature and autochthonous dengue cases (rs = .999, p = 000) and imported dengue cases with autochthonous dengue cases (rs = .162, p = 000). A negative binomial multivariate regression was used to analyze the expansion of dengue to each monthly unit of temperature, rainfall, and imported dengue cases over 34 years. The results indicated that temperature (IRR = 2.198; 95% CI [1.903, 2.538]) and precipitation (IRR = .991; 95% CI [.988, .994]) were predictors for the geographic expansion of dengue fever in Southeast Florida. The positive social changes include the use of the results to develop an understanding of how climatic variables and migration may influence the expansion of dengue fever to nonendemic regions. The results can be used by public health authorities to address risk factors and to formulate evidence-based decisions in regard to prevention and education concerning dengue fever.

A vibration isolator is designed to reduce the vibration and structure borne noise transmitted from a vibratory source, such as machinery and equipment, to the supporting structure. The vibration and structure borne noise transmitted depends upon the dynamic properties of the foundation, the source mounting point and the vibration isolator. Therefore knowledge of the frequency dependent dynamic properties of vibration isolators is a necessary part of the acoustic prediction and control/reduction process. Vibration isolators may be characterised by measuring their four-pole parameters. A measurement procedure is proposed that employs the floating mass method, measures the direct forces and corrects for the errors introduced by the direct force measurement. Compared to the basic method, it extends the frequency limits of measurement in both directions. The development of a novel vibration isolator test facility that implements the proposed measurement procedure is described, and its satisfactory operation is experimentally demonstrated. The vibration isolator test facility is capable of characterizing vibration isolators commonly used in industrial and maritime applications, under service conditions. A method is proposed for measuring the four-pole parameters of a uni-directional asymmetrical vibration isolator under static load. The method is called the two masses method, and is suitable for determining the four???pole parameters of active vibration isolators with feedback control. The method is also applicable to uni-directional symmetrical and bi-directional symmetrical and bi-directional asymmetrical vibration isolators. It may be regarded as a universal method for characterising vibration isolators. Experimental data is presented and the method is validated. Modelling of vibration isolators is complicated by the highly non-linear nature of their rubber elements. The notion of an effective rubber cylinder is proposed to account for the barrelling of rubber elements under static load. Consequently, a general static compression model is proposed that applies to vibration isolators having unfilled and filled rubber elements of regular prismatic shapes. The model predicts the dependence of the four-pole parameters on the compression ratio of the rubber element. The predictions derived from the effective rubber cylinder and general static compression model agree excellently with experimental work of this study and other researchers.

Cette thèse porte sur les méthodes numériques pour les équations aux dérivées partielles (EDP) non-linéaires dégénérées, ainsi que pour des problèmes de contrôle d'EDP non-linéaires résultants d'un nouveau problème de transport optimal. Toutes ces questions sont motivées par des applications en mathématiques financières. La thèse est divisée en quatre parties. Dans une première partie, nous nous intéressons à la condition nécessaire et suffisante de la monotonie du $\theta$-schéma de différences finies pour l'équation de diffusion en dimension un. Nous donnons la formule explicite dans le cas de l'équation de la chaleur, qui est plus faible que la condition classique de Courant-Friedrichs-Lewy (CFL). Dans une seconde partie, nous considérons une EDP parabolique non-linéaire dégénérée et proposons un schéma de type ''splitting'' pour la résoudre. Ce schéma réunit un schéma probabiliste et un schéma semi-lagrangien. Au final, il peut être considéré comme un schéma Monte-Carlo. Nous donnons un résultat de convergence et également un taux de convergence du schéma. Dans une troisième partie, nous étudions un problème de transport optimal, où la masse est transportée par un processus d'état type ''drift-diffusion'' controllé. Le coût associé est dépendant des trajectoires de processus d'état, de son drift et de son coefficient de diffusion. Le problème de transport consiste à minimiser le coût parmi toutes les dynamiques vérifiant les contraintes initiales et terminales sur les distributions marginales. Nous prouvons une formule de dualité pour ce problème de transport, étendant ainsi la dualité de Kantorovich à notre contexte. La formulation duale maximise une fonction valeur sur l'espace des fonctions continues bornées, et la fonction valeur correspondante à chaque fonction continue bornée est la solution d'un problème de contrôle stochastique optimal. Dans le cas markovien, nous prouvons un principe de programmation dynamique pour ces problèmes de contrôle optimal, proposons un algorithme de gradient projeté pour la résolution numérique du problème dual, et en démontrons la convergence. Enfin dans une quatrième partie, nous continuons à développer l'approche duale pour le problème de transport optimal avec une application à la recherche de bornes de prix sans arbitrage des options sur variance étant donnés les prix des options européennes. Après une première approximation analytique, nous proposons un algorithme de gradient projeté pour approcher la borne et la stratégie statique correspondante en options vanilles.

Cette thèse porte sur l'étude du positionnement optimale des réseaux de capteurs pour la localisation de sources. Nous avons étudié deux approches: l'approche basée sur les performances de l'estimation en termes d'erreur quadratique moyenne et l'approche basée sur le seuil statistique de résolution (SSR).Pour le première approche, nous avons considéré les bornes inférieures de l'erreur quadratique moyenne qui sont utilisés généralement pour évaluer la performance d'estimation indépendamment du type d'estimateur considéré. Nous avons étudié deux types de bornes: la borne Cramér-Rao (BCR) pour le modèle où les paramètres sont supposés déterministes et la borne Weiss-Weinstein (BWW) pour le modèle où les paramètres sont supposés aléatoires. Nous avons dérivé les expressions analytiques de ces bornes pour développer des outils statistiques afin d'optimiser la géométrie des réseaux de capteurs. Par rapport à la BCR, la borne BWW peut capturer le décrochement de l'EQM des estimateurs dans la zone non-asymptotique. De plus, les expressions analytiques de la BWW pour un modèle Gaussien général à moyenne paramétré ou à covariance matrice paramétré sont donnés explicitement. Basé sur ces expressions analytiques, nous avons étudié l'impact de la géométrie des réseaux de capteurs sur les performances d'estimation en utilisant les réseaux de capteurs 3D et 2D pour deux modèles des observations concernant les signaux sources: (i) le modèle déterministe et (ii) le modèle stochastique. Nous en avons ensuite déduit des conditions concernant les propriétés d'isotropie et de découplage.Pour la deuxième approche, nous avons considéré le seuil statistique de résolution qui caractérise la séparation minimale entre les deux sources. Dans cette thèse, nous avons étudié le SSR pour le contexte Bayésien moins étudié dans la littérature. Nous avons introduit un modèle des observations linéarisé basé sur le critère de probabilité d'erreur minimale. Ensuite, nous avons présenté deux approches Bayésiennes pour le SSR, l'une basée sur la théorie de l'information et l'autre basée sur la théorie de la détection. Ces approches pourront être utilisée pour améliorer la capacité de résolution des systèmes.

<p>Flexographic printing is a common printing method in the packaging field. The printing method is characterized primarily by the flexible printing plate and the low viscosity inks which make it suitable for use on almost any substrate. The object of this study was to obtain further knowledge of the some important mechanisms of flexographic printing and how they influence the print quality. The thesis deals with printing primarily on board and liner but also on newsprint with water-borne ink using a full-scale flexographic central impression (CI) printing press. Several printing trials have been performed with a focus on the chemical interaction between the ink and substrate and the physical contact between the ink-covered printing plate and the substrate.</p><p>Multicolour printing exposes the substrate to water from the water-containing ink. The emphasis was to investigate the relation between print quality and water-uptake of the paper surface with heat and water. Printing trials was carried out on substrates possessing a hydrophobic, and also a rather hydrophilic surface using a regular commercial water-borne ink. The favorable effect which water or surfactant solution had on the hydrophobic substrate with regard to print mottle could depend on its surface compressibility in combination with the hydrophobic nature of its surface that could affect the wetting properties.</p><p>Conventional printing involves physical contact between plate and ink and between ink and substrate. A method for measuring the dynamic nip pressure using thin load cells is presented. Print quality was influenced by the plate material. A correction procedure taking into account the size of the sensor was developed in order to estimate the maximum dynamic pressure in the printing nip. An attempt was made to identify essential mechanical and chemical parameters, and also geometrical properties of the plate that affected print quality. Laboratory printing trials were carried out and a multivariate analysis was applied for evaluation of print quality data. The impact of the plate properties on print quality was evident. The essential properties of the plate that influence print quality were the small-scale roughness and long-scale roughness.</p>

Several vector-borne and zoonotic diseases have emerged or re-emerged in Europe over these last decades. Besides climate change that influences disease risk at a regional scale, landscape changes could be responsible for local heterogeneities in disease risk. Spatial epidemiology tries to understand and predict spatial variations in disease risk by using spatial tools and spatially-explicit modelling methods. This study investigated the impact of fine-grained landscape patterns on the transmission of vector-borne and zoonotic infections in terms of habitat suitability for vectors and/or hosts and of exposure of people to infectious agents. This was studied through three human diseases emerging or at risk of re-emergence in Europe: the rodent-borne Puumala hantavirus, the tick-borne Lyme borreliosis and the mosquito-borne malaria infections. Statistical models were first used to study the relationships between environmental variables and host abundance, host prevalence, and human cases of Puumala hantavirus. Environmental factors were also combined with socio-economic factors to explain Puumala hantavirus and Lyme borreliosis incidence rates. The combination of factors explaining disease transmission and the complexity of such systems led to the development of an innovative, spatially-explicit modelling method: multi-agent simulation (MAS). The MALCAM simulation model was developed to assess the risk of malaria re-emergence in southern France and simulates spatial and temporal variations in contact rate between people and potential malaria vectors. The effect of changes in potential drivers of malaria re-emergence was also simulated. The different case studies showed that fine-grained landscape patterns influence the presence and abundance of vectors and hosts. Moreover, environmental conditions may also influence disease transmission through pathogen dispersal and the exposure of people to infectious agents. Finally, this study showed that people-vector contacts not only depend on the spatial distribution of people and potential vectors, but also on their behaviours and interactions.

The rapid expansion of major cities in the west Europeancountries has accentuated the need to exploit every potentialsite for new establishments, e.g. areas over train tunnels andnear railway tracks in general. A significant impediment toexploit such areas is the structure-borne noise generated bythe train traffic, which is transmitted into buildings via theground. Reliable prediction methods and cost-effective noisecontrol measures are therefore needed and are also the objectof the present work. In this thesis, the studied buildings areconsidered as wave-guides for the sound transmitted from theground. The work is restricted to the case of hard ground suchas granite. The chosen technique permits comparison betweendifferent potential measures to reduce the transmission ofstructure-borne sound upward in buildings. It is shown that thedesign of the load-bearing structures is important in thiscontext, and a design with relocated columns has givenpromising results. It is also shown that the stiffness of theground plays an important role in the transmission process.This leads to the idea that a sand layer between the foundationof the building and the bedrock may reduce the transmission.New methods have thus been developed in the course of this workto evaluate the stiffness of the layer using approximate andexact techniques. Results are presented and a comparison ismade with previous results for a "normal" building and it isshown that the insertion of sand layer has a potential toconsiderably reduce the sound level in the building. <b>Keywords:</b>Ground-borne noise, railway noise, in-planewaves, wave-guides, scattering, propagation constant, inputmobility, elastic stratum, dual integral equations.

Bacterial genomes provide records of the molecular processes associated with emergence and evolution of different bacterial lifestyles. This thesis is based on whole-genome comparisons within the genus Bartonella, an excellent model system for studies of host- and vector-specificity and infection outcome in animal-associated bacteria. The louse-borne human specialist and trench fever agent Bartonella quintana was contrasted to the flea-borne generalist relatives Bartonella henselae and Bartonella grahamii, which cause asymptomatic infection in cat and mouse respectively. While B. henselae is commonly isolated from humans, and causes cat scratch disease, there is only one reported case of B. grahamii human infection. The gene complements of the three species are nested like Russian dolls with the smaller genome (B. quintana) being entirely contained in the medium sized (B. henselae), which in turned is contained in the largest (B. grahamii). Size differences reflect differences in the horizontally and vertically acquired gene content, and in the number of genus- and species- specific genes, owing to differential impact of bacteriophages and plasmids, and to different degrees of genome decay. These processes can be attributed to the three distinct lifestyles. Comparisons with other alpha-proteobacteria suggest that the Bartonella genus as a whole evolved from plant-associated species, and that horizontal transfer, in particular of genes involved in interaction with the host, played a key role in the transition to animal intracellular lifestyle. The long-term genome decay associated with this lifestyle is most advanced in the host-restricted B. quintana. The broad host-range species B. grahamii has the largest genome and the largest proportion of auxiliary DNA of the three, probably because it has access to a larger gene pool. In encodes all the known pathogenicity determinants found in the genomes of B. henselae and B. quintana, suggesting that these genes primarily evolved to facilitate colonization in the reservoir host.

<p>Everyday thousands of nurses are rendering bedside nursing care in health care settings as a result they are exposed to blood, body fluids and sharp objects that are contaminated with Hepatitis B, Hepatitis C and HIV. Therefore they are at risk of getting infected. In 1996, standard precautions were implemented by the Centre of Disease Control to reduce the risk of transmission of micro-organisms from any source of infection in the hospital. In the year 2008, the three tertiary hospitals together in the Western Cape reported that they had 733 needle prick injuries. Therefore the aim of the study was to determine if nurses comply with and have adequate knowledge of standard precautions. A non-experimental design and a self administered questionnaire were used to collect the data for the study. The study was done at Tygerberg Hospital and the participants (n=143) that were involved in the study were all nursing categories (professional, enrolled nurse and auxiliary nurse). Stratified random sampling was used to ensure that there was a representation of all the nurses working in the different modules at Tygerberg Hospital. Therefore three wards were randomly selected from each module and all the nurses on duty working in the three selected wards were given a questionnaire by the Assistant Director of the specific module. After the data was collected it was analysed through the statistical package for social sciences. The findings of the study showed that nurses have inadequate knowledge regarding standard precautions and the mean score of the nurses overall self reported compliance of standard precautions was 87.5%. The results also showed that when patients are HIV positive nurses intend to over comply the use of personal protective equipment. No association was found between the nurses&rsquo / knowledge and compliance regarding standard precautions. It is therefore important that every nurse should be educated about the basic principles of standard precautions and also the policies and protocols of infection control in order to prevent each nurse from getting infected. Training needs to be implemented starting in the wards through the unit manager to improve all the nurses&rsquo / knowledge and practice.</p>

In this research water dispersed epoxy varnishes were produced by reacting solid epoxy resin with ethylene diamine (EDA) and maleinized fatty acids of linseed oil. Maleinized fatty acid (MFA) was produced by the maleinization process, in which, fatty acid and maleic anhydride were reacted under nitrogen atmosphere. Maleinization was performed in order to insert hydrophilic groups to the fatty acid chains, which were then inserted to the backbone of the epoxy resin. This was done to give water dispersibility to the hydrophobic epoxy resin. Solid epoxy resin was dissolved in 1,4-dioxane. Ethylene diamine was then added to the solution at 50&deg / C, and stirred for 4 hours. Then the temperature was increased to 80oC and kept for 2 hours. Maleinized fatty acids were then introduced, and the reaction was carried out at 90oC for 10 hours. 1,4-dioxane was used for the removal of the water, which forms as the byproduct. Then the driers were added. The carboxylic groups of the maleinized fatty acid were neutralized by morpholine and the product was dispersed in water. The varnish was applied on test panels and left for air-drying for 24 hours and then baked at 140&deg / C for 5 hours. The free epoxy content was determined by pyridinium-chloride titration and it was seen that all the epoxy groups reacted. Also, produced fatty acid was characterized by FTIR spectroscopy and maleinized fatty acid was characterized by H-NMR and FTIR spectroscopy. Hardness, bending, impact resistance, gloss, and abrasion resistance tests were carried out on hardened varnish specimens. The samples generally showed good mechanical and physical properties. While the baking time was increased the hardness of product increased. Samples showed superior impact resistance, gloss, and flexibility.