Microorganisms are widespread in all ecosystems and play critical roles in nature. They are major players in global biogeochemical cycles that are fundamental in nutrient cycling. Molecular ecology surveys that investigate the microbial diversity of many different environments have revealed an impressive diversity of microbes in nature and have highlighted our inability to cultivate the vast majority of them in the laboratory. The improvement of our ability to grow uncultivable microbes in laboratory conditions will help us in this challenging task. Standard cultivation methods that have helped to bring to culture many relevant microorganisms in the past century are, however, characterized by limitations which hamper the isolation of novel microbes. For this reason, alternative cultivation strategies have been developed in recent decades which have allowed to expand the collection of environmentally relevant but poorly represented microbial strains. The use of such novel approaches for investigating the microbial diversity of underexplored natural ecosystems, such as sub-tropical mangrove forests, can result in the isolation, in laboratory conditions, of bacterial strains belonging to previously undescribed taxa. Mangroves are unique environments exposed to strong selection forces with respect to other marine environments, including high temperatures, salinity and oligotrophy. I hypothesize that these unique combinations of environmental features have selected microbiomes with unique characteristics. The aim of this PhD research is to explore the bacterial diversity of the Red Sea mangrove ecosystem, by applying an alternative cultivation strategy that uses oligotrophic conditions and long incubation time. I also exploited the diffusion chamber to cultivate bacterial taxa belonging to rarely isolated or even novel genera. This approach allowed me to isolate four novel bacterial taxa. Using 16S rRNA gene sequencing, the isolated bacteria were identified as one novel species and three novel genera belonging to Alpha-proteobacteria, Bacteroidetes, and Firmicutes, respectively. These isolates were further characterized and described through genomic, phylogenetic, chemotaxonomic, and phenotypic analysis to describe their ecological significance in the ecosystem of origin (i.e., mangrove sediments). This study reveals that the extreme conditions of the Red Sea mangroves have selected a unique and yet mostly untapped culturable microbiome with great potential for environmental applications.

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Text in German / Zusammenfassung Die vorliegende Untersuchung geht von der Beobachtung aus, dass die postmoderne Gesellschaft tendenziell isolierend auf die Menschen wirkt. Demgegenüber wohnt der Kirche ein Gemeinschaftspotential inne, das eine greifbare Alternative für vereinsamte Menschen anbieten kann. Diese Untersuchung stellt nun die zentrale Frage, wie die Kirche ihr gemeinschaftsförderndes Potential effektiver in die Gesellschaft einbringen kann. Hierzu werden zunächst die soziologischen und theologischen Voraussetzungen geklärt, denen dann, anhand einer begrenzten empirischen Studie, praktische Erfahrungen von Menschen mit kirchlicher Gemeinschaft an die Seite gestellt werden. Zuletzt wird die zeitgenössische Gemeindebauliteratur vergleichend herangezogen, um schlussendlich die zentrale Frage dieser Untersuchung mit einigen praktischen Vorgehensvorschlägen zu beantworten. Summary of Dissertation This study has its roots in the observation, that the postmodern society has a tendency to isolate the people. In contrast to this, the church has an inherent potential of community, which can offer a concrete alternative for isolated people. This study now asks the central question, how the church can be enabled to bring their community-promoting potential more effectively into the society. For this, firstly the sociological and theological conditions are clarified, to which then, on the basis of a limited empirical study, practical experiences of people with church community are placed beside. At last, the contemporary literature of church growth is consulted comparatively, in order to finally answer the central question of this study by some practical procedure suggestions. / Philosophy, Practical and Systematic Theology / M.Th. (Practical Theology)

The classification of the family Felidae (cats) is problematical due to the conservative nature of their morphology. Some workers classify the family into as many as 20 genera (Ewer, 1973) while others divide it into three genera (Walker et al., 1964). Such studies have largely been based on morphological and behavioural characters. Recently, molecular studies, namely, protein albumin immunological distances (Collier and O'Brien, 1985) and protein electrophoresis (Randi and Ragni, 1991) have been used to try and resolve the problems underlying this family. To complement the previous studies, in the present study we use mitochondrial (mt) DNA to construct a· phylogeny of eight members of the southern African Felidae namely, African wild cat, Felis lybica; domestic cat, Felis catus; caracal, Caracal caracal; European wild cat, Felis sylvestris; leopard, Panthera pardus; lion, Panthera leo; and cheetah, Acynonyx jubatus. Mitochondrial DNA (mt DNA) was utilized instead of nuclear DNA since it accumulates point mutations at a rate which is 5 to 10 times as fast as the nuclear DNA and is therefore particularly useful for studying more closely related organisms between sub-species, species and genera. Its apparent potential to be used as a tool for constructing genealogical trees and time scales makes it a method of choice in evolutionary studies. We used the restriction mapping approach to generate data for phylogenetic analysis. Restriction mapping was utilized since it gives good resolution at the species and genus level and evolutionary estimates derived from this method are considered more accurate than those obtained by methods such as the restriction fragment size comparison. We have also attempted to develop the methodology for sequencing part of the cytochrome b region of mt DNA following polymerase chain reaction (PCR) amplification. Both cladistic and distance approaches were used for phylogenetic construction. This study will be both of academic value and may have relevance to practical conservation management since these molecular approaches help to identify or confirm specific status especially with respect to the relationship between the domestic cat and the African and the European wild cats. Furthermore, such approaches can be used at the intraspecific level to address problems in biogeography and population genetics. Our results are in concordance with the previously determined morphological studies and albumin immunological distance studies. The restriction maps for the African wild cat and the domestic cat are identical, emphasizing their close relationship and the African origin of the domestic cat. The European wild cat showed a slight variation with the African wild cat or the domestic cat with four different restriction sites and a sequence divergence of 0.9. This suggests that the common ancestral mt DNA of these cats existed about 450 000 years ago. The lion and the leopard are monophyletic in both cladistic and distance approaches. The precise placement of caracal has yet to be resolved but it is deeply rooted in the phylogenetic analysis which would be more consistent with a separate generic status of the latter species rather than its inclusion within either Felis or Panthera. The distance analyses are consistent with the placement of the cheetah as the most distantly related species amongst the eight Felid species examined.

Pox viruses have been demonstrated in over 60 types of wild and exotic birds as well as domestic birds. Avipox viruses have been isolated and characterised from fowls, quails, canaries, parrots and lovebirds. This work describes the first isolation of a poxvirus from Jackass penguins (Spheniscus dermersus) and the characterisation of the virus as a separate species of penguinpox virus.

Capripoxviruses are of particular interest as live recombinant vectors for use in the veterinary field, since their host-range is restricted to cattle, goats and sheep. The work presented in this thesis is a preliminary study undertaken on the South African Neethling vaccine strain of lumpy skin disease virus (LSDV). As a departure point towards the eventual identification of strong promoter areas in the 143 kb genome of LSDV, a portion of its genome was cloned. Three methods for purification of LSDV DNA were compared, to determine which yielded the best quality DNA for cloning. DNA extracted directly from infected cells was excessively contaminated with bovine host-DNA, complicating the cloning of LSDV DNA. The use of pulsed field gel electrophoresis solved the contamination problem, by separating viral DNA from bovine DNA. However, insufficient amounts of viral DNA for cloning purposes, could be recovered from the gel. Sufficient amounts of good quality LSDV DNA was obtained by extraction from purified virions. Purified LSDV DNA was digested with various restriction enzymes to identify those which yielded several 4-1 0 kb fragments, for cloning into the Bluescribe plasmid transcription vector. Enrichment for large fragments (8-1 0 kb) was achieved by sucrose density centrifugation. Cloned fragments were analysed by Southern blot hybridisation to verify their viral origin. Hybridisation studies indicated that several unique regions of the LSDV genome were cloned as Pst I and Bam HI fragments respectively, i.e. the cloned fragments contained no overlapping regions. In total, 71.25 kb of the DNA of the LSDV Neethling vaccine strain has been cloned, representing approximately 50% of the viral genome. The availability of these clones now paves the way for further molecular investigations of the LSDV Neethling genome, including identification of promoter regions. A trial gene, which will be cloned and expressed in LSDV, namely the cloned VPS-gene of bluetongue virus serotype 4, was prepared and its nucleotide sequence determined. Homopolymer sequences present at the terminal ends of the gene as a result of the original cloning strategy, are known to interfere with expression and were removed by means of the polymerase chain reaction (PCR). The nucleotide sequence of the resulting PCR-tailored BTV4 VPS-genewas determined and used to deduce the amino acid sequence of the protein. The gene is 1638 bp in length and encodes a protein of 526 aa. Conserved sequences, 6 bp in length and unique to the 5'- and 3'terminal ends of all BTV genes, were detected at the termini of the tailored gene, confirming that the original clone was a full-length copy of the gene. Amplification by PCR did not mutate the open reading frame (OAF) of the gene, since it was of similar length to that reported for 5 other BTV serotypes. With a view to future investigations, including the identification of promoter sequences in the LSDV genome, a preliminary investigation of LSDV protein synthesis was undertaken, to acquire some knowledge of the growth cycle of the virus. Eighteen putative virus-specific proteins were identified by radio-labelling infected cells with [³⁵S]-methionine. By pulse-labelling infected cells with [³⁵S]methionine at various times post infection (p.i.), viral proteins were first detected at 16 hr p.i. It is, however, unlikely that the early phase of viral replication commences as late as 16 hr p.i. and these results might be attributed to various problems, such as the low multiplicity of infection used and that host protein shut-down was inefficient, thus masking the presence viral proteins. In conclusion, this investigation resulted in the cloning of 71,25 kb of the LSDV genome, the tailoring and sequencing of the BTV4 VPS gene and the identification of 18 putative LSDV proteins. This now paves the way for further research to develop LSDV as a vaccine vector.

Les noyaux de systèmes d'exploitation manipulent des données fournies par les programmes utilisateur via les appels système. Si elles sont manipulées sans prendre une attention particulière, une faille de sécurité connue sous le nom de Confused Deputy Problem peut amener à des fuites de données confidentielles ou l'élévation de privilèges d'un attaquant. Le but de cette thèse est d'utiliser des techniques de typage statique afin de détecter les manipulations dangereuses de pointeurs contrôlés par l'espace utilisateur. La plupart des systèmes d'exploitation sont écrits dans le langage C. On commence par en isoler un sous-langage sûr nommé Safespeak. Sa sémantique opérationnelle et un premier système de types sont décrits, et les propriétés classiques de sûreté du typage sont établies. La manipulation des états mémoire est formalisée sous la forme de lentilles bidirectionnelles, qui permettent d'encoder les mises à jour partielles des états et variables. Un première analyse sur ce langage est décrite, permettant de distinguer les entiers utilisés comme bitmasks, qui sont une source de bugs dans les programmes C. / Operating system kernels need to manipulate data that comes from user programs through system calls. If it is done in an incautious manner, a security vulnerability known as the Confused Deputy Problem can lead to information disclosure or privilege escalation. The goal of this thesis is to use static typing to detect the dangerous uses of pointers that are controlled by userspace. Most operating systems are written in the C language. We start by isolating Safespeak, a safe subset of it. Its operational semantics as well as a type system are described, and the classic properties of type safety are established. Memory states are manipulated using bidirectional lenses, which can encode partial updates to states and variables. A first analysis is described, that identifies integers used as bitmasks, which are a common source of bugs in C programs. Then, we add to Safespeak the notion of pointers coming from userspace. This breaks type safety, but it is possible to get it back by assigning a different type to the pointers that are controlled by userspace. This distinction forces their dereferencing to be done in a controlled fashion. This technique makes it possible to detect two bugs in the Linux kernel: the first one is in a video driver for an AMD video card, and the second one in the ptrace system call for the Blackfin architecture.

Nos maisons sont intelligentes grâce aux appareils fournissant des services (sécurité, efficacité énergétique,...). Des fournisseurs de services non fiables veulent profiter de la maison intelligente en développant des services hébergés dans une passerelle domotique embarquée. Cette passerelle doit être suffisamment robuste contre les problèmes logiciels. Partager les ressources de passerelle entre applications permet de fournir des services riches, mais provoque des risques de conflits de partage de ressources. Nous abordons le problème des conflits de partage des ressources dans la passerelle domotique, investiguant la prévention lorsque possible, et la détection et la résolution sinon. Notre première contribution «Jasmin» est un intergiciel pour développer, déployer et isoler les applications embarqués natives à base de composants et orientées services. Jasmin utilise les conteneurs Linux pour une isolation à faible coût. Notre seconde contribution «Incinerator» est un système dans la machine virtuelle Java (JVM) qui résout le problème des références obsolètes en Java, qui causent des fuites mémoire importantes en OSGi, augmentant ainsi les risques de conflits de partage de mémoire. Incinerator détecte et élimine les références obsolètes. Pour détecter les conflits de partage de mémoire, nous présentons la troisième contribution : système de surveillance mémoire dans la JVM. Le système compte précisément les ressources consommées pendant les interactions entre applications et fournit des statistiques d'utilisation de mémoire pour les différents fournisseurs de services partageant la passerelle. / Our homes become smart thanks to devices providing services (security, energy efficiency,…). Untrusted service providers want to take advantage of the smart home by developing services hosted by an embedded smart home gateway. The gateway should be robust enough to handle software problems. Sharing resources of the gateway between service providers allows providing richer services but raises risks of resource sharing conflicts. We addresses the problem of resource sharing conflicts in the smart home gateway, by prevention when possible, and by detection and resolution otherwise. Our first contribution "Jasmin" is a middleware to develop, deploy and isolate native embedded component-based and service-oriented applications. Jasmin uses Linux containers for lightweight isolation. Our second contribution "Incinerator" is a subsystem in the Java Virtual Machine (JVM) aiming to resolve the problem of Java stale references, which cause significant memory leaks in an OSGi-based smart home gateway, hence increasing the risks of memory sharing conflicts. Incinerator detects and eliminates stale references. In order to detect memory sharing conflicts, we propose our third contribution: memory monitoring subsystem in the JVM. The system accurately accounts for resources consumed during cross-application interactions, and provides snapshots of memory usage statistics for the different service providers sharing the gateway.

Plants require ten elements in appreciable quantity and several others in smaller amount for their continued and normal growth. Three of these necessary elements, nitrogen, phosphorus, and potassium are most important because they occur in the soil in quantities which are usually small in proportion to that needed by the plants. Of these three, nitrogen is in most cases the limiting factor because of the ease with which in may be leached from the soil and comparatively large amount assimilated by plants. These factors coupled with the inhibiting high cost of artificially replacing it in the form of commercial fertilizers, make its conservation and efficient utilization of the utmost importance.

The isolation, purification, and partial characterization of a novel iron-containing protein from the sulfate-reducing anaerobic bacterium, Desulfovibrio gigas, is described. The highly insoluble protein was isolated from the cell debris following osmotic shock of the bacteria. The insoluble fraction consistently contained about 90% of the cell-associated iron. This protein was treated with acid, chelating agents, detergents and proteases in order to study their effect on the iron solubility. The results of elemental analysis of a crude protein preparation were 5.3% iron, 2.9% sulfur and 11 .9% nitrogen. An independent colorimetric iron analysis showed 6.4% iron. The iron could be dissociated from the protein by treatment with 5% sodium dodecyl sulfate. The iron-free protein was purified by a combination of organic extraction and DEAE-cellulose chromatography. The purified protein showed only one major band, MW 14,000, by SDS polyacrylamide gel electrophoresis. The protein could be reconstituted upon treatment with an appropriate mixture of FeS and B-mercaptoethanol. The reconstituted protein had the same physical and chemical properties as the native protein. The amino acid composition was not unusual except for the high isoleucine content. The amino acid composition was similar to that of a number of membrane proteins. Growth and iron assimilation in D. gigas were studied and the form of iron present in the medium were also examined. The intracellular distribution of iron and sulfur assimilated from the medium was determined. The presence of an iron chelating compound was also briefly examined. Some interesting observations and experiments dealing with colored iron complexes and their characteristics are included. An unusual basic component tentatively identified as cadaverine is also discussed briefly.