Due to the lead spike and its related health concern in the DC area, Point-of-Use (POU) filters were installed at public schools to reduce lead concentrations in water. However, the installation of POU filter could possibly lead to the growth of bacteria inside the filters, which could lead to health concerns. Therefore, the potential effects of POU filters on microbial growth was investigated. To explore the cause of filter effects on microbial growth, a sampling campaign was carried out between July and December 2017 from 25 outlets within 5 elementary schools in the DC area. The applicability of flow cytometry results as a quantification method was validated and then used to quantify the biological growth. Our results revealed that the installation of POU filters may lead to nitrification and an increase in microbial growth. Along with the increase in microbial growth, the microorganism community "fingerprints" based on flow cytometry data showed that the installation of filter could also shift the community distribution of bacteria based on their morphology. This study serves as a preliminary study to investigate the mechanics of microbial colonization on POU filters. / Master of Science

Notre recherche consiste à comprendre quels sont les effets des jeux vidéo de simulation d’animaux virtuels sur les conceptions du vivant, en particulier sur la distinction entre ce qui est vivant et ce qui ne l’est pas. Pour ce faire, il s’agit d’identifier les différences conceptuelles entre les populations de joueurs et de non-joueurs aux jeux vidéo de simulation d’animaux virtuels. Tout d'abord, nous avons fait une enquête exploratoire identifiant les pratiques vidéo ludiques des enfants. Cette enquête a permis de sélectionner les deux jeux les plus utilisés par les enfants de cet âge : Talking TOM et POU. Notre étude porte plus particulièrement sur ces deux jeux. Un questionnaire a été diffusé au Liban et en France pour étudier la façon dont les joueurs et les non-joueurs à ces deux jeux conçoivent le vivant. Au total 916 enfants âgés de 9 à 12 ans ont rempli ce questionnaire. Au Liban, le questionnaire a été suivi de 21 entretiens avec des élèves. Les questionnaires ont été traités statistiquement afin de faire émerger les différences et les similitudes entre les populations de joueurs et de non-joueurs en France et au Liban. Les entretiens ont été analysés par une analyse thématique de contenu suivie par une analyse lexicale et ont permis une exploitation plus qualitative des résultats. Les résultats montrent que les entretiens et les questionnaires convergent fortement vers l’hypothèse d’une influence des jeux sur la construction de la notion de vie chez les joueurs des deux pays. En effet, au Liban et en France les utilisateurs de TOM et POU ont des conceptions significativement plus anthropomorphiques, animistes et anthropocentriques que ceux qui n’y jouent pas. / Our research is to understand the effects of video games simulating virtual animals on the concepts of life, especially the distinction between what is alive and what is not. To do this, it is a question of identifying the conceptual differences between the populations of players and non-players in virtual animal simulation video games. First, we did an exploratory survey identifying children's playful video practices. This survey allowed selecting the two most used games by children of this age: Talking TOM and POU. Our study focuses on these two games. A questionnaire has been distributed in Lebanon and France to study how players and non-players in TOM and / or POU design the living. A total of 916 children aged 9 to 12 completed this questionnaire. In Lebanon, 21 interviews with students followed the questionnaire. The questionnaires were statistically analyzed to reveal the differences and similarities between the populations of players and non-players in France and Lebanon. The interviews had been analyzed by a thematic analysis of content followed by a lexical analysis and allowed a qualitative exploitation of the results. The results show that interviews and questionnaires strongly converge on the hypothesis of an influence of games on the construction of the notion of life among players of both countries. Indeed, in Lebanon and France users of TOM and POU have significantly more anthropomorphic, animistic and anthropocentric conceptions than those who do not play it.

Le pou de tête et le pou de corps sont deux écotypes indiscernables occupant chacun une niche écologique différente. Le pou de corps représente une menace réelle pour l'Homme en raison de son rôle de vecteur dans la transmission de trois maladies graves pour l'Homme à savoir: le typhus épidémique, la fièvre des tranchées et la fièvre récurrente. Dans cette thèse, nous avons obtenu des résultats concrets dans chacune des thématiques abordées. En effet, nous avons (i) mis en place un outil moléculaire qui permet de différencier pour la première fois entre le pou de tête et le pou de corps qui a montré efficacité sur le terrain, (ii) mis en évidence l'existence d'un nouveau clade mitochondrial (Clade D) renfermant des poux de tête et des poux de corps susceptible de vectoriser Bartonella quintana et Yersinia pestis, (iii) retracé les migrations humaines à travers l'analyse de poux anciens provenant de différentes périodes et localisations, (iv) démontré pour la première fois que Pediculus mjobergi est génétiquement proche du pou humain et confirmé l'hypothèse qu'à l'origine Pediculus mjobergi était un pou humain qui a été transféré aux singes du Nouveau Monde par les premiers Hommes à avoir atteint le continent américain il y a des milliers d'années et (v) mis en place un outil de détection et de contrôle de la résistance moléculaire des poux à la perméthrine. Cet outil fut particulièrement utile dans l'étude clinique que nous avons menée pour déterminer si l'utilisation de sous-vêtements imprégnés d'insecticide offrait une protection efficace à long terme contre les poux de corps infestant les personnes sans-abri. / Head louse (Pediculus humanus capitis) and body louse (Pediculus humanus humanus) are two indistinguishable ecotypes each occupying an ecological niche: hair for head louse and clothing for the body louse. Body louse represents a real threat to humans because of its role as vector for the transmission of three deleterious diseases namely epidemic typhus, trench fever and relapsing fever.In this thesis, we obtained concrete results that have led to scientific publications. Indeed, we (i) implemented a molecular tool to differentiate for the first time between head and body louse, (ii) we highlighted the existence of a fourth mitochondrial clade (Clade D) comprising head and body lice that can vectorize Bartonella quintana and Yersinia pestis, (iii) we traced human migration through the analysis of ancient lice from different periods and different area, (iv) we demonstrated for the first time that Pediculus mjobergi is genetically close to human louse and confirmed the hypothesis that initially Pediculus mjobergi was a human louse has been transferred to New World monkeys by the first humans who have reached the American continent thousands of years ago and (v) we have implemented a tool for detecting and monitoring the molecular resistance to permethrin of body lice that parasite sheltered homeless persons in Marseille. This tool was particularly useful in the clinical study we conducted to determine whether the use of long-lasting insecticide-treated underwear provides effective long-term protection against body lice in homeless persons.

L'étude des magmas issus des points chauds est essentielle pour la compréhension de la structure et de la composition des panaches mantelliques et de leurs interactions avec la lithosphère océanique. Jusqu'au début des années 1990, les données sur les îles Marquises ne provenaient que de missions exploratoires. De ce fait, les modèles géochimiques de fonctionnement du point chaud marquisien publiés de 1986 à 1993 ne reposaient que sur un échantillonnage très partiel. Ils ont fortement sous-estimé les interactions entre les magmas issus du point chaud et la lithosphère océanique et négligé la complexité de l'origine des laves évoluées (trachytes et phonolites), parfois très abondantes. Depuis 1995, des études ponctuelles plus précises ont montré que l'évolution géochimique des laves au cours du temps variait considérablement d'une île à l'autre, reflétant l'hétérogénéité à petite échelle du panache ainsi que des interactions lithosphère – asthénosphère complexes. Le programme de cartographie des îles du groupe central des Marquises (Nuku Hiva, Ua Huka, Ua Pou) a été initié par le Bureau de Recherches Géologiques et Minières (BRGM) en 2000. Il a permis l'étude de leurs structures, ainsi qu'un échantillonnage détaillé que nous avons exploité du point de vue pétrologique et géochimique. L'archipel des Marquises repose sur une croûte océanique formée à l'axe de la dorsale Pacifique-Farallon entre 53 et 49 Ma et fortement épaissie sous la partie centrale de l'archipel où le Moho atteint des profondeurs de 15 à 20 km. L'application d'un modèle thermique permet de tester l'hypothèse d'une mise en place rapide d'un épais sous-placage mafique contemporain du volcanisme de point chaud récent exprimé en surface (5,8-0,4 Ma). La subsidence thermique prédite par ce modèle diminue rapidement pendant les trois premiers millions d'années, depuis 250 à 50 m/Ma. Or, des terrasses d'abrasion marine, dont l'origine est attribuée au dernier haut niveau marin interglaciaire daté à 125 ka, bordent toutes les îles des Marquises à 2 m d'altitude. Aucune différence de subsidence n'est observée entre les îles les plus anciennes et celles les plus récentes. Ces observations ne sont pas en accord avec le modèle de subsidence thermique postérieure à un événement de sous-placage récent et sont, par contre, compatibles avec l'hypothèse d'un épaississement ancien dû à la mise en place d'un plateau océanique dans le futur substratum de l'archipel. L'île de Ua Pou est connue de longue date pour l'abondance exceptionnelle de ses phonolites. Sa première cartographie systématique permet une estimation du volume de sa partie émergée (27,5 km3) incluant 18 km3 de phonolites (65 %) mises en place en deux étapes distinctes, 2 km3 d'autres laves intermédiaires et évoluées (8 %) et 7,5 km3 de laves mafiques (27 %). L'île de Ua Pou présente une série alcaline allant des basanites jusqu'aux phonolites avec une distribution bimodale basanites-phonolites très nette, ainsi qu'une lacune de Daly se traduisant par l'absence de phonotéphrites. Les analyses d'éléments majeurs et en trace, ainsi que les isotopes du Sr, Nd, Pb couplés aux données chronologiques (K-Ar) permettent de discuter l'histoire pétrogénétique complexe de l'île. L'activité aérienne de Ua Pou débute vers 4 Ma par la mise en place de tholéiites à olivine dérivant d'une source mantellique de signature HIMU jeune. Elle reprend vers 2,9 Ma avec la fusion partielle d'une source hétérogène à signature dominante EM II + HIMU jeune qui produit des liquides basanitiques primaires. Ces liquides se mettent en place à la fois en profondeur et en surface et évoluent par cristallisation fractionnée pour former les téphrites. En même temps, la refusion en profondeur de ce matériel basanitique produit des magmas téphriphonolitiques en laissant un résidu riche en amphibole. Ces magmas évoluent alors par cristallisation fractionnée pour former des liquides phonolitiques, lesquels peuvent subir une contamination par l'eau de mer. Alors que la production de ces deux types de phonolites continue de façon relativement synchrone avec la mise en place des basanites, de nouveaux processus fonctionnant en système ouvert apparaissent entre environ 2,6 et 2,4 Ma. Ils permettent la formation de téphriphonolites et de phonolites ayant assimilé du matériel de type plagiogranitique à signature HIMU et la genèse de phonolites extrêmement différenciées ayant incorporé du matériel de la croûte océanique à signature DMM. Ainsi, l'île de Ua Pou peut être considérée comme un exemple typique de série intraocéanique dans laquelle la prédominance des laves évoluées reflète leur origine par fusion partielle de précurseurs mafiques suivie de la contamination crustale plutôt que par cristallisation fractionnée. L'île de Nuku Hiva est constituée de deux volcans emboîtés : le volcan-bouclier externe (volcan du Tekao) formé de tholéiites à olivines et le volcan interne de Taiohae présentant une série alcaline continue depuis les basaltes jusqu'aux trachytes. Il existe d'importantes différences géochimiques entre ces deux volcans, le premier présentant une signature à tendance DMM et le second une signature de type EM II prédominante. Cette dualité est attribuée à des variations des taux de fusion partielle d'un manteau-source hétérogène. Au sein du volcan interne, les laves intermédiaires (hawaiites et mugéarites) dérivent des basaltes par cristallisation fractionnée sous forte pression d'eau, dominée par le fractionnement de l'amphibole en proportions importantes (jusqu'à 25%). L'origine des laves évoluées (benmoréites et trachytes) de Nuku Hiva demeure problématique. Leur signature isotopique très différente de celle des basaltes et laves intermédiaires du volcan interne amène à envisager 1) la cristallisation fractionnée des magmas mafiques-intermédiaires couplée avec l'assimilation de matériel océanique à signature fortement EM II ou 2) leur origine par fusion partielle de précurseurs mafiques non échantillonnés sur la partie aérienne de l'île. Ainsi, l'île de Nuku Hiva montre que les signatures géochimiques des laves varient au cours du temps. Cette île peut être considérée comme un exemple typique de série intraocéanique dans laquelle l'évolution des laves est contrôlée par des processus de cristallisation fractionnée sous forte pression d'eau et l'origine des laves évoluées met en évidence des interactions lithosphère-asthénophère complexes. Le modèle de point chaud le plus adéquat pour rendre compte de la forte hétérogénéité géochimique des Marquises est celui d'un panache très hétérogène contenant des éléments de signature de croûte océanique subductée (HIMU) et de sédiments terrigènes (EM II) répartis de façon aléatoire. Au terme de sa remontée, le panache incorpore du manteau sublithosphérique appauvri (DMM). Cette signature DMM peut également refléter soit la fusion de la base de la lithosphère océanique au-dessus du panache, soit des interactions entre les magmas ascendants et les roches de cette lithosphère. Les variations des taux de fusion partielle et l'interaction entre les liquides basaltiques et la croûte océanique au sein de réservoirs intracrustaux permettent également de rendre compte de l'hétérogénéité des laves au sein d'une même île. Bien que ces effets ne soient pas documentés pour l'ensemble des îles de l'archipel, il est possible de supposer que l'essentiel de l'hétérogénéité géochimique des laves des Marquises résulte du mélange en proportions variables des trois pôles mantelliques EM II, HIMU et DMM. En faisant l'hypothèse que le panache contient uniquement les pôles EM II et HIMU et que le pôle DMM seul est contenu dans la partie crustale de la lithosphère océanique, il est possible de faire un modèle de mélange entre ces trois pôles et en deux étapes : 1) le mélange entre les pôles EM II et HIMU permet d'estimer les proportions de chacun de ces composants dans les liquides issus du panache, 2) le mélange entre ces liquides hybrides et la lithosphère océanique à signature DMM, ce qui conduit à une estimation quantifiée des interactions entre le panache et la lithosphère océanique. Ainsi, la contribution du pôle DMM est dominante pour les îles d'Eiao, Nuku Hiva, Ua Huka et Hiva Oa. Celle du pôle EM II est dominante pour les laves alcalines de Ua Pou alors que celle du pôle HIMU domine à Fatu Hiva et pour les tholéiites de Ua Pou. Pour ces deux dernières îles, la contribution du pôle DMM est la plus restreinte. Pour la majorité des îles, la contribution du pôle DMM est importante ce qui peut indiquer : 1) que le pôle DMM est également présent dans la composition du panache profond, et/ou : 2) que l'incorporation de matériel appauvri DMM modifie considérablement la composition des liquides directement issus du panache. Cette dernière hypothèse est compatible avec celle de l'existence d'un plateau océanique dans le substratum marquisien, dont les roches à signature DMM prédominante interagiraient avec les magmas issus du panache.

MESHWR / Department of Hydrology and Water Resources / Water borne diseases due to inadequate and unsafe drinking water is a global challenge that has led to a significant number of deaths and illnesses reported annually. These diseases are prevalent in less-developed countries, especially in rural areas where there is shortage of basic infrastructure and inadequate funds for piped water systems in individual households. Community members are forced to resort to collecting water from communal water points and later storing the water in containers for daily use. Recontamination of microbiologically safe drinking water during and after collection from the water source has been recognised as a problem; hence treating water at household level is one way to provide potable water for affected communities. The microbiological quality of household water may be improved by using point-of-use treatment technologies such as chemical disinfection, solar disinfection and ceramic water filters. Some of these technologies are expensive, less effective and difficult to implement in rural communities. This research thus focused on ceramic water filters and finding an appropriate method for silver application so as to produce filters that are effective in both the provision of clean drinking water and the release of silver levels that are safe for human consumption. An assessment of the efficiency of ceramic water filters made with silver nitrate as point-of -use water treatment device in Dertig Village, North West Province, South Africa was carried out. During production of filters made with silver nitrate, the filters undergo firing in an electric kiln and ionic silver is reduced to metallic nanopatches dispersed throughout the porous ceramic media. Both filters made with silver nitrate and conventional silver nanoparticles impregnated ceramic water filters were manufactured at the PureMadi Dertig Ceramic Filter Facility, South Africa. Resulting filters were evaluated and quantified for total coliform and E. coli removal as well as silver concentration in the effluent. Ceramic water filters made with silver nitrate had a high removal efficiency for total coliforms (94.7%) and E. coli (99.3%). A comparison of the performance of filters made with silver nitrate and silver nanoparticles in the provision of potable water was carried out and results showed that the different filters had similar levels of total coliform and E. coli removal, although the silver nitrate filters produced the highest average removal of 97.23% while silver nanoparticles filters produced the lowest average removal of 85.43%. Reasonable silver levels were obtained in effluent from all filters. Average effluent silver levels were 0.07±0.04mg/L, 0.6±1.10 mg/L and 0.8±1.0mg/L for 1 g, 2 g and silver nanoparticle filters, respectively (below the EPA and WHO standard of 100 mg/L). Because silver nitrate filters resulted in the lowest effluent silver concentrations, this could potentially increase the effective life span of the filter. A cost analysis of the process proved that it was cheaper to produce ceramic water filters using silver nitrate as the chemical can be purchased locally and also eliminates labour related costs. Thus, filters made using silver nitrate could potentially improve performance, reduce production costs, and increase safety of production for workers. The results obtained from this study will be applied to improve the ceramic filtration technology as point-of-use water treatment device in an effort to reduce health problems associated with microbial contamination of water stored at household level. / NRF

Point-of-use (POU) drinking water treatment is a common method of providing drinking water in disaster relief situations when critical water infrastructure is damaged. In these cases, POU treatment devices can be used to treat local water until relief organizations set up more permanent water provision methods. One such POU technology is PŪR® Purifier of Water, a combined coagulation/flocculation and disinfection chemical treatment sachet produced by Procter & Gamble. PŪR® has been shown to treat contaminated water to meet water quality standards and guidelines set by the U.S. EPA for water purifiers and by the World Health Organization and The Sphere Project for emergency relief. However, the standard two-bucket method of use for PŪR® has two primary drawbacks: (1) the need for appurtenances that may not be readily available in disaster relief situations and (2) lack of a means to protect treated water from re-contamination post-treatment. An alternative to the two-bucket method is a waterbag system under development at the California Polytechnic State University, San Luis Obispo. The waterbag is a ten-liter plastic bladder with integrated filter that incorporates an all-in-one approach to drinking water treatment during emergencies. In previous studies, the first version of the waterbag consistently met World Health Organization and The Sphere Project emergency drinking water guidelines, but did not meet the pathogen reduction requirements of the U.S. EPA Guide Standard and Protocol for Testing Microbiological Water Purifiers. A second (Mark II) version, with internal mixing baffles and a microfilter, was developed to overcome the inability of the first design to meet the U.S. EPA guidelines. The main purposes of the research presented herein were to (1) optimize the method of use and baffle configuration for the improved Mark II version of the waterbag, (2) determine ability of the waterbag to treat test waters with challenging initial water quality conditions, and (3) test the ability of the Mark II design and optimized method to meet the U.S. EPA Guide Standard and Protocol for Testing Microbiological Water Purifiers. For the first and second objectives, the main metric of treatment performance was the extent of flocculation, which was characterized by the turbidity of waterbag supernatant after 30 minutes of settling. The waterbag procedure was varied in several ways. The variables tested were mixing duration, mixing motion type, and the effect of a mixing delay. Several waterbag baffle designs were tested to determine the physical configuration of the waterbag which resulted in best turbulence during mixing. In addition, experiments were performed to test the ability of the Mark II waterbag to treat waters with various initial qualities, such as high organic carbon content and elevated E. coli concentrations. The results of these experiments helped to prepare for a final test in meeting the pathogen removal requirements of the U.S. EPA Guide Standard and Protocol for Testing Microbiological Water Purifiers. The procedure determined to be optimal for the Mark II waterbag treatment included five minutes of mixing using rapid 180° twisting motions at a moderate frequency of seventy 180°-twists per minute. The optimal baffle design was a 12.7 cm-wide internal mixing baffle with two cut circular holes for the promotion of turbulence during mixing. The desired post-treatment chlorine residual was achieved for different durations depending on initial organic carbon concentration. Optimal PŪR® dose to provide pathogen removals required by the U.S. EPA in the presence of Challenge Water conditions was two sachets per 10 L of water to be treated. The optimization of these design and operational procedures led to the ability of the Mark II waterbag to meet the pathogen, turbidity, pH, and non-microbiological constituent removals required by the U.S. EPA, The Sphere Project, and World Health Organization for emergency relief.

<p> Heavy metals, especially arsenic, have become a hot research topic due to their high toxicity and low removal efficiency in drinking water. Biofouling is one of the main factors affecting the removal efficiency of point-of-use (POU) water filtration systems. However, limited information is available on the effect of biofouling on heavy metal removal by POU systems. The aim of this study was to investigate how biofouling affects the removal efficiency of heavy metals,  especially arsenic, by different POU systems. Daily water use patterns in the U. S. households were simulated under laboratory conditions for the operation of POU systems. Sodium acetate was added to tap water to simulate an assimilable organic carbon source that contributes to biofouling formation and the concentration of sodium acetate gradually increased from 100 μg/L to 400 μg/L.  Sodium meta-arsenate (100 μg/L) was added to tap water to test its removal efficiency by POU  systems. Biofouling development and metal removal efficiency were monitored and correlated.  The results showed that arsenic removal efficiency and biofouling were positively correlated in both the activated carbon (AC) and reverse osmosis (RO) POU systems. Other conditions, such as temperature and flow rate, were negatively correlated with metal removal efficiencies in both systems. Overall, biofouling has been shown to contribute to improved removal efficiency of arsenic by POU, and the promotion effect was more significant in AC systems than in RO systems.  The results may contribute to an improved understanding of the maintenance of POU systems for heavy  metal removal </p>

There has been a recent increase in the adoption of point-of-use (POU) household water filters as an alternative to untreated tap water or bottled water. POU filters certified for lead removal have recently been distributed by the hundreds of thousands in communities amid water lead crises, as a temporary solution to protect consumers from elevated water lead levels. This thesis rigorously examines the efficacy of POU lead certified filters in removing lead under a wide range of conditions, and evaluates premature clogging due to iron and associated impacts on the cost analysis of using filters instead of bottled water. In testing ten brands of POU devices against up to four different waters for lead removal, most devices consistently removed lead to below the 5 µg/L FDA bottled water standard. However, several failures were documented, including manufacturing flaws, premature clogging, and inconsistency between duplicate filters. When waters containing more difficult to treat lead particulates were synthesized, treated water often had lead concentrations greater than the 5 µg/L bottled water standard and sometimes were even over the 15 µg/L EPA action level. In some cases, less than 50% of the particulate lead was removed by the filter, thereby replicating some problems with these devices identified in the field. While POUs usually reduced water lead concentrations by at least 80%, a combination of manufacturing issues and difficult to treat waters can cause treated water to exceed expectations. Consumers often purchase POU devices to remove particles and lead in waters that also contain high iron, prompting studies to examine the role of iron on filter performance. When we exposed two brands of pour-through POUs to waters with both high lead and iron, lead removal performance was generally not compromised, as treated water typically had lead concentrations less than 5 µg/L. One case was observed in which lead passed through a set of filters at high levels in association with iron, confirming expectations that in some waters iron could cause formation of lead particulates that are difficult to remove. High levels of iron sometimes rapidly clogged the POU filters, preventing them from reaching their rated capacity and increasing operational costs and time to filter water. Specifically, 50% (3/6) of the filters tested clogged prematurely at an iron concentration of 0.37 mg/L, 66% (4/6) at 1 mg/L and 100% (6/6) at 20 mg/L. A cost analysis for POUs vs. bottled water demonstrated that in waters with higher iron, store-brand bottled water was often the more cost-effective option, especially when iron levels were significantly higher than the EPA Secondary Maximum Contaminant Level (0.3 mg/L). The lower costs of bottled water in these situations was even more apparent if consumer time was factored into the analysis. / Master of Science / There has been a recent increase in the use of household water filters as an alternative to tap water or bottled water. Filters that are certified for lead removal have recently been distributed by the hundreds of thousands in communities amid water lead crises, as a temporary solution to protect consumers from elevated water lead levels. This thesis rigorously examines the effectiveness of these filters under a wide range of conditions. When tested against up to four different waters for lead removal, most filters consistently reduced lead to below the concentrations allowed in bottled water. In cases where the filters did not perform as expected, several filter failure modes were identified, including manufacturing flaws, filter clogging, and inconsistency between duplicate filters. In addition to these failures, when a water that contained particulate lead that was difficult to filter, as little as 50% of the lead was removed. While household filters often significantly reduce water lead concentrations, a combination of manufacturing issues and difficult to treat waters can cause poor performance. In many cases, consumers purchase filters to remove particles or lead in waters that also contain iron, which caused us to investigate the effect of iron on filter performance. When two brands of pour-through filters were tested against waters with both lead and iron, lead removal performance was generally not compromised. One exceptional case was observed where both high levels of lead and iron passed through the filters, leading us to believe that iron in some waters could create conditions where lead is more difficult to remove. In many cases, the presence of iron caused filters to dramatically slow down or clog. Premature clogging due to iron prevented filters from reaching their rated capacity and, in doing so, significantly increased cost and filter times. A cost analysis for filters vs. bottled water demonstrated that in waters with higher iron, store-brand bottled water was often the more cost-effective option, especially in waters with higher levels of iron. The lower costs of bottled water in these situations was even more apparent if consumer time was factored into the analysis.

Reproduction de : Thèse de doctorat : Biologie moléculaire et cellulaire : Lille 2 : 2008. / Résumé en français et en anglais. Titre provenant de l'écran-titre. ADN = Acide Désoxyribonucléique. Bibliogr. f. 184-202.

This diploma thesis deals with a geographical research of the peripheral region of Kaplice with the orientation on social capital. The administrative district of municipality is located in the southern part of South Bohemia in the district of Český Krumlov. The diploma thesis consists of two parts. The theoretical part concentrates on the terms like social capital, periphery and on the basic geographical characteristic of the monitored area. The subsequent practical part deals with the specific research that consists of the analysis of secondary data and survey. All acquired data are processed and presented in the form of tables and graphs with following evaluation and comparison of results with other similar researches.