L’anémone de mer symbiotique Anemonia viridis possède cinq morphes définis à l’aide de critères morphologiques. Premièrement, le statut taxonomique de trois des morphes d’A. viridis (var. rufescens, rustica et smaragdina) a été précisé à l’aide de marqueurs moléculaires basés sur des gènes de stress et des marqueurs RAD. Nous avons pu déterminer que ces trois morphes ne formaient qu’une seule espèce et mis en évidence quatre lignées génétiques indépendantes sur base de la géographie (trois en mer Méditerranée, une dans la Manche). Par l’utilisation des variations des séquences ITS2, nous n’avons pu détecter aucune implication du symbiote (Symbiodinium sp.) dans la différenciation des morphes, mais nous avons révélé une composition en symbiotes divergente entre les lignées génétiques indépendantes de l’hôte animal. Par ailleurs, A. viridis se développe dans des environnements particulièrement contrastés, faisant d’elle un modèle d’étude idéal pour l’étude de l’adaptation locale chez les Cnidaires. Par conséquent, l’adaptation locale chez A. viridis a été testée en comparant des populations venant de sites aux conditions environnementales contrastées (surface vs. profondeur et lagune vs. mer). Une recherche de loci outliers sur des marqueurs RAD et des marqueurs de gènes de stress n’a toutefois révélé aucun gène candidat dans l’adaptation locale par rapport aux conditions environnementales testées. Ce travail a donc permis de définir A. viridis comme un organisme extrêmement plastique capable de posséder un fort polymorphisme intrinsèque et de s’acclimater à des habitats contrastés. / The symbiotic sea anemone Anemonia viridis has five morphs described using morphological traits. First, the taxonomical status of three of the morphs of A. viridis (var. rufescens, rustica and smaragdina) was studied using stress gene markers and RAD markers. We revealed that the three morphs were not different species, but that A. viridis was split into four polymorphic independent genetic lineages based on geographical origin (three in the Mediterranean Sea, one in the English Channel). Using ITS2 sequence variation, we could not detect any implication of the symbiont (Symbiodinium sp) in the morph differentiation, but we revealed a divergence in symbiont composition among the geographic independent lineages of the animal host. If no effect of the symbiont was detected, a variable distribution of the ITS2 variants based on geography was revealed. Moreover, A. viridis lives in highly contrasted environments, making it an ideal species to study local adaptation. Thus, local adaptation was tested on A. viridis by comparing populations coming from contrasted environments (shallow vs. deep and lagoon vs. sea). Using RAD and stress genes markers in a search for outlier loci, we revealed no candidate adaptive genes under our environmental conditions. In conclusion, Anemonia viridis seems to be a very plastic organism, with a high intrinsic polymorphism and a high acclimation potential.

The purpose of the research was to determine how educators could be motivated to implement internet technology in education. The literature study highlighted the need for e-learning while suggesting that educator support would not be achieved easily. The empirical study, however, revealed that at the international school examined, educators accept internet learning and demonstrate a willingness to introduce it into their pedagogy, were a blended approach to be adopted. Technological and psychological barriers had already been breached, as e-learning was taking place in a non-threatening environment. Educators were being empowered to experiment with e-learning in their subject areas. The study revealed that, having already embraced e-learning methodology educators would continue to do so if they could clearly perceive the benefits to be achieved. The study also showed that given a technologically nurturing environment, it would not be difficult to motivate educators to introduce internet technology into their pedagogy. / Educational Studies / M.Ed. (Adult Education)

No description available.

Approximately 10% of sequenced bacterial genomes are multipartite, consisting of two or more large chromosome-sized replicons. This genome organization can be found in many plant, animal, and human pathogens and symbionts. However, the advantage of harbouring multiple replicons remains unclear. One species with a multipartite genome is Sinorhizobium meliloti, a model rhizobium that enters into N2-fixing symbioses with various legume crops. In this work, S. meliloti derivatives lacking one or both of the secondary replicons (termed pSymA and pSymB) were constructed. Phenotypic characterization of these strains, including growth rate, metabolic capacity, and competitive fitness, provided some of the first experimental evidence that secondary replicons evolved to provide a niche specific advantage, improving fitness in a newly colonized environment. These results were further supported by characterizing the symbiotic phenotypes of 36 large-scale pSymA and pSymB deletion mutants. To further this analysis, an in silico S. meliloti genome-scale metabolic network reconstruction was developed and flux balance analysis used to examine the contribution of each replicon to fitness in three niches. These simulations were consistent with the hypothesis that metabolic pathways encoded by pSymB improve fitness specifically during growth in the plant-associated rhizosphere. Phylogenetic analysis of a pSymB region containing two essential genes provided a clean example of how a translocation from the primary chromosome to a secondary replicon can render the secondary replicon essential. Moreover, an experimental analysis of genetic redundancy indicated that 10-15% of chromosomal genes are functionally redundant with a pSymA or pSymB encoded gene, providing an alternative method for how secondary replicons can become essential and influence the evolution of the primary chromosome. Finally, the work presented here provides a novel framework for forward genetic analysis of N2-fixing symbiosis and the identification of the minimal N2-fixing symbiotic genome, which will help facilitate the development of synthetic symbioses. / Thesis / Doctor of Philosophy (PhD) / Many bacteria that enter into symbiotic or pathogenic relationships with plants, animals, and humans contain a genome that is divided into multiple chromosome-like molecules. One example is the N2-fixing legume symbiont Sinorhizobium meliloti, whose genome contains three chromosome-sized molecules. Here, the functions associated with each molecule in the S. meliloti genome were examined through a combination of experimental genetic analyses and computer based simulations. Results from these approaches suggested that adaptation to unique environments selected for the evolution of secondary chromosome-like molecules, with each predominately contributing to growth in a specific environment, including environments associated with an eukaryotic host. The genes on these replicons are therefore prime targets for manipulation of bacterium-host interactions, and represent reservoirs of valuable genes for use in synthetic biology applications. Additionally, the genome reduction approach employed in this study laid out a ground work for identification of the minimal N2-fixing symbiotic genome. This represents a crucial step towards successfully engineering improved nitrogen fixation, and the engineering of synthetic N2-fixing symbioses involving non-legumes and/or non-rhizobia.

Africa’s rapid adoption of the mobile phone is quickly closing the digital divide in voice services. But, just as one divide is closing, another one is widening. Consumers almost everywhere are demanding more services and higher Internet access data rates. In the developing world the knowledge gained through access to information is creating unprecedented opportunities and is having a dramatic impact on the way people live and work. Africa, however, has been largely left behind in the shift to broadband. Increasing the availability and affordability of broadband services is thus high on the agenda for policy makers in Africa, though it will require major efforts from both government and the private sector. Fundamental to the all efforts to close the “digital divide” is the need to provide a ubiquitous and affordable access network that will enable distribution of broadband services to anywhere, and anytime throughout Africa. While many kinds of broadband services are being offered to the African population, the currently available services have failed to reach the majority of Africans living in rural areas. This poses a very pertinent question that justifies further investigations: why have the existing broadband services failed to satisfy Africa’s need for a ubiquitous digital communication service. The lack of penetration of the existing services makes it clear that a different technology and service offering is needed, a service offering that is affordable to the large consumer market segment and which can complement the mobile and ADSL broadband networks to provide services to all of Africa on a cost effective basis. This research work investigates the current business and technology domains and develops new knowledge and the insights that are required firstly to understand why existing broadband services are failing to reach rural Africa and secondly to understand what criteria must be satisfied to deliver broadband access services to the mass consumer Africa market. The research work focuses on the interrelationships between markets, technology and business of the consumer broadband market and defines new thinking as reference to provide guidance to the future development of more suitable broadband offerings for the rural African market. The study centres around three principal areas of knowledge contribution. Analysis of the primary factors impacting the delivery of broadband services Firstly the study addresses the current market dynamics and technology realities to determine two critical aspects: 1) Can the mass market afford broadband services or will it remain the privilege of the higher income groups? And, 2) Can existing mobile broadband , ADSL and satellite access services meet the demands to service the mass market or is an alternative technology option required? Through analytical review the study determined that there is a large, and growing, middle class market that can afford broadband access services. This market sector is quantified in terms of consumer income levels and demographic user data. The study formulates the commercial and service criteria applicable to a broadband access service on servicing this target market. The study further investigates the availability, affordability and market penetration of the current mobile and ADSL broadband services and found that the available service options cannot effectively meet the current and future demand. The limitation in meeting the current market demand leads to a large under serviced consumer market in Africa. The study proposes a unique approach to quantify the specific under-serviced gap, which will not be met by currently available broadband technologies. The technology comparative study provides new insight into the limitations of mobile 3G broadband services and why this technology will not be able to meet the future demand for consumer broadband services in Africa. The technology study furthermore quantifies the advantages of using satellite technology to implement a mass consumer broadband service in Africa. The study proves that the ubiquitous nature and rapid deployment capabilities of satellite access networks provides distinct benefits when deploying a mass consumer network which makes satellite the technology of choice for consumer broadband services. We then continue to assess the ability of existing satellite broadband offerings to satisfy the needs of African end-users, and find that those offerings have been optimized for the needs and affordability levels of customers from the develop world. The result is that satellite broadband services aimed at the African end-user is primarily used by corporate and institutional customers, with little penetration of the consumer market. This finding provides the motivation for developing a business model that can leverage available technology to effectively service the African consumer market. Innovation of new concepts to support a viable broadband business strategy The mobile prepay model as well as the DStv pay-TV subscription services have demonstrated the need for a specific business innovation to ensure successful market adoption of new technologies. Both these industries have demonstrated that innovative approaches in the commercialization of technology solutions are critical to ensure the mass adoption thereof. The second section of the study therefore focuses on the innovations that are required to overcome the obstacles as identified in section 1 in order to arrive at a business strategy and business model that will prove to be viable in the delivery of broadband services to the rural African consumer market. The first challenge is the selection of the most appropriate technology platforms and the architectural design of the delivery systems to effectively service the mass consumer market. In order to adapt the business models employed by existing satellite broadband service providers the study defines the following two specific business innovation concepts that contribute to a new business paradigm for mass market broadband access services: 1) Through applied billing model innovation the study defines a new billing structure for broadband services and set a completely new paradigm for users to influence the cost of the service. The new billing model provides end-user the capability to adapt their broadband usage patterns to meet their budget constraints. 2) To successfully deliver a technology service to an emerging market requires a very specific organisational structure that effectively integrates knowledge, capability and funding while minimizing risk and uncertainty. The study proposes a new symbiotic organisational structure that elegantly combines capability and knowledge while minimizing funding requirements to ensure the acceptable market development risk. Development of a business model simulator for satellite broadband service delivery The deployment of a new type of satellite broadband service to rural Africa on an experimental basis is too expensive to be conducted for research purposes. A more practical approach that is also widely used in other domains of engineering is to construct a simulated model of the system being studied. The third knowledge contribution area of the study therefore focuses on constructing a mathematical model of the expected behavior of a business operation that provides satellite based broadband services to the African market. This simulator can be applied to quantitatively analyze various existing or proposed new business strategies. The business model simulation integrates all the business, market, technology and commercial relationships that impacts on the expected behavior of such an operation and provides a quantified model of expected business behavior based on the underlying dynamics of the satellite broadband industry. The development and validation of the business model simulator represents a unique contribution to this industry as no results of a similar model that represents the operations of a satellite broadband access service provider has been published before. The model empowers Service Providers and industry stakeholders to analyze different business strategies and to quantify the impact of various business decisions. In general it can be stated that this research work adds knowledge and insight to the field of applied business strategy as applicable to providing advanced technology-based services for emerging markets. The final outcome of this research study is the business model simulator. It integrates various market and business elements as well as satellite network engineering practises into an integrated financial cost modelling, business scenario planning and engineering network design tool. Through this integration of known disciplines the study provides an additional extension to the field of satellite business engineering. / PhD (Electronic Engineering), North-West University, Potchefstroom Campus, 2013

Africa’s rapid adoption of the mobile phone is quickly closing the digital divide in voice services. But, just as one divide is closing, another one is widening. Consumers almost everywhere are demanding more services and higher Internet access data rates. In the developing world the knowledge gained through access to information is creating unprecedented opportunities and is having a dramatic impact on the way people live and work. Africa, however, has been largely left behind in the shift to broadband. Increasing the availability and affordability of broadband services is thus high on the agenda for policy makers in Africa, though it will require major efforts from both government and the private sector. Fundamental to the all efforts to close the “digital divide” is the need to provide a ubiquitous and affordable access network that will enable distribution of broadband services to anywhere, and anytime throughout Africa. While many kinds of broadband services are being offered to the African population, the currently available services have failed to reach the majority of Africans living in rural areas. This poses a very pertinent question that justifies further investigations: why have the existing broadband services failed to satisfy Africa’s need for a ubiquitous digital communication service. The lack of penetration of the existing services makes it clear that a different technology and service offering is needed, a service offering that is affordable to the large consumer market segment and which can complement the mobile and ADSL broadband networks to provide services to all of Africa on a cost effective basis. This research work investigates the current business and technology domains and develops new knowledge and the insights that are required firstly to understand why existing broadband services are failing to reach rural Africa and secondly to understand what criteria must be satisfied to deliver broadband access services to the mass consumer Africa market. The research work focuses on the interrelationships between markets, technology and business of the consumer broadband market and defines new thinking as reference to provide guidance to the future development of more suitable broadband offerings for the rural African market. The study centres around three principal areas of knowledge contribution. Analysis of the primary factors impacting the delivery of broadband services Firstly the study addresses the current market dynamics and technology realities to determine two critical aspects: 1) Can the mass market afford broadband services or will it remain the privilege of the higher income groups? And, 2) Can existing mobile broadband , ADSL and satellite access services meet the demands to service the mass market or is an alternative technology option required? Through analytical review the study determined that there is a large, and growing, middle class market that can afford broadband access services. This market sector is quantified in terms of consumer income levels and demographic user data. The study formulates the commercial and service criteria applicable to a broadband access service on servicing this target market. The study further investigates the availability, affordability and market penetration of the current mobile and ADSL broadband services and found that the available service options cannot effectively meet the current and future demand. The limitation in meeting the current market demand leads to a large under serviced consumer market in Africa. The study proposes a unique approach to quantify the specific under-serviced gap, which will not be met by currently available broadband technologies. The technology comparative study provides new insight into the limitations of mobile 3G broadband services and why this technology will not be able to meet the future demand for consumer broadband services in Africa. The technology study furthermore quantifies the advantages of using satellite technology to implement a mass consumer broadband service in Africa. The study proves that the ubiquitous nature and rapid deployment capabilities of satellite access networks provides distinct benefits when deploying a mass consumer network which makes satellite the technology of choice for consumer broadband services. We then continue to assess the ability of existing satellite broadband offerings to satisfy the needs of African end-users, and find that those offerings have been optimized for the needs and affordability levels of customers from the develop world. The result is that satellite broadband services aimed at the African end-user is primarily used by corporate and institutional customers, with little penetration of the consumer market. This finding provides the motivation for developing a business model that can leverage available technology to effectively service the African consumer market. Innovation of new concepts to support a viable broadband business strategy The mobile prepay model as well as the DStv pay-TV subscription services have demonstrated the need for a specific business innovation to ensure successful market adoption of new technologies. Both these industries have demonstrated that innovative approaches in the commercialization of technology solutions are critical to ensure the mass adoption thereof. The second section of the study therefore focuses on the innovations that are required to overcome the obstacles as identified in section 1 in order to arrive at a business strategy and business model that will prove to be viable in the delivery of broadband services to the rural African consumer market. The first challenge is the selection of the most appropriate technology platforms and the architectural design of the delivery systems to effectively service the mass consumer market. In order to adapt the business models employed by existing satellite broadband service providers the study defines the following two specific business innovation concepts that contribute to a new business paradigm for mass market broadband access services: 1) Through applied billing model innovation the study defines a new billing structure for broadband services and set a completely new paradigm for users to influence the cost of the service. The new billing model provides end-user the capability to adapt their broadband usage patterns to meet their budget constraints. 2) To successfully deliver a technology service to an emerging market requires a very specific organisational structure that effectively integrates knowledge, capability and funding while minimizing risk and uncertainty. The study proposes a new symbiotic organisational structure that elegantly combines capability and knowledge while minimizing funding requirements to ensure the acceptable market development risk. Development of a business model simulator for satellite broadband service delivery The deployment of a new type of satellite broadband service to rural Africa on an experimental basis is too expensive to be conducted for research purposes. A more practical approach that is also widely used in other domains of engineering is to construct a simulated model of the system being studied. The third knowledge contribution area of the study therefore focuses on constructing a mathematical model of the expected behavior of a business operation that provides satellite based broadband services to the African market. This simulator can be applied to quantitatively analyze various existing or proposed new business strategies. The business model simulation integrates all the business, market, technology and commercial relationships that impacts on the expected behavior of such an operation and provides a quantified model of expected business behavior based on the underlying dynamics of the satellite broadband industry. The development and validation of the business model simulator represents a unique contribution to this industry as no results of a similar model that represents the operations of a satellite broadband access service provider has been published before. The model empowers Service Providers and industry stakeholders to analyze different business strategies and to quantify the impact of various business decisions. In general it can be stated that this research work adds knowledge and insight to the field of applied business strategy as applicable to providing advanced technology-based services for emerging markets. The final outcome of this research study is the business model simulator. It integrates various market and business elements as well as satellite network engineering practises into an integrated financial cost modelling, business scenario planning and engineering network design tool. Through this integration of known disciplines the study provides an additional extension to the field of satellite business engineering. / PhD (Electronic Engineering), North-West University, Potchefstroom Campus, 2013

Different theoretical approaches and interpretations offer diverse delineations and clusters of Enneagram type in terms of Horney’s interpersonal trends of moving toward, moving against and moving away from people. The present study reports the results of an empirical investigation into the relationship between Enneagram type and Horney’s interpersonal trends. A sample of 2 3 participants completed the Test of Object Relations (TOR) and 125 of these participants completed the Horney-Coolidge Tridimensional Inventory (HCTI). Two one-way, between-groups multivariate analyses of variance revealed differences between Enneagram types for each of the HCTI interpersonal trends of compliance, aggression and detachment and the TOR dimensions of separation anxiety, symbiotic merging, narcissism, egocentricity, social isolation and fear of engulfment. For each trend, an Enneagram type could be identified as a unique marker or benchmark of the trend. However, the empirical result does not offer clear support for one theoretical approach or viewpoint rather than another. / Psychology / M. A, (Psychology)

Le traitement biologique des eaux usées urbaines et industrielles reste une activité ayant un impact négatif sur l’environnement et sur le changement climatique par l’émission des gaz à effet de serre (GES), notamment le CO2. Les changements innovants au niveau des procédés de traitement des eaux usées par l’intégration des flocs de microalgues-bactéries ont abouti à des procédés multitrophiques sans apport d’O2 et sans dégagement du CO2. Il s'agit d'une étude de faisabilité de ces flocs-MaB pour la photobioremédiation des polluants (organiques et minéraux) et pour la production de biomasse valorisable en bioénergie dans le cadre de l'économie circulaire. En présence de la lumière, les flocs-MaB ont été intégrés dans des photobioréacteurs à biomasse fixe afin d'assurer un traitement durable des eaux usées grâce aux échanges symbiotiques entre les micro-oragnismes en terme de nutriments et de gaz. L'encapsulation des flocs-MaB dans des billes de PVA-alginate a montré l'effet des conditions physico-chimiques et hydrodynamiques sur l'élimination des polluants et l'évolution multicellulaire des flocs au sein des réacteurs à multi-échelles. Par ailleurs, la biomasse multitrophique immobilisée sur des supports biodégradables d'olive (OPP) et sur des disques en PVC a assuré une meilleure performance des bioréacteurs à lit fluidisé et à disques rotatifs, respectivement, pour la bioremédiation des eaux usées. Les propriétés des supports (porosité, rugosité et structure) et les comportements hydrodynamiques ont été contrôlés pour favoriser l'attachement des biofilms multitrophiques. Le développement de biofilm montre l'effet des interactions multitrophiques entre les microalgues et les bactéries sur l'élimination des composés organiques (DCO) et nutriments (ammonium et phosphore). La biomasse des flocs-MaB a été récupérée et réutilisée pour le traitement du digestat liquide à l'issu du digesteur et pour améliorer la production de biométhane par une co-digestion anaérobie. Ce procédé multitrophique et intégré permet d'obtenir Zéro déchet à la sortie du processus / The biological treatment of urban and industrial wastewaters represents a process with a negative impact on the environment and on climate change through the emission of greenhouse gases (GHG), particularly CO2. In the presence of light, microalgae-bacteria flocs (MaB-flocs) have been integrated into photobioreactors with fixed biomass to ensure a sustainable wastewater treatment without O2 supply and CO2 release. The entrapment of flocs in PVA-alginate beads has shown the effect of physicochemical and hydrodynamic conditions on the elimination of pollutants and the multicellularity evolution within multi-scale bioreactors. In addition, the immobilization of biomass on biodegradable olive carriers and on PVC disks provided a better performance of fluidized bed and rotating discs bioreactors, respectively, for the bioremediation of wastewater. The properties of the supports (porosity, roughness, and structure) and the hydrodynamic behaviors have favored the attachment of multitrophic biofilms. Biofilm development shows the effect of multitrophic interactions between microalgae and bacteria on the organic compounds (COD) and nutrients (ammonium and phosphorus) removals. The MaB-flocs biomass was recovered and reused for the treatment of the digestate and to improve the production of biomethane by anaerobic co-digestion. This integrated multitrophic technology makes it possible to obtain zero wastes at the end of the process

A subset of 199 Melissotarsus insularis and 130 Diaspididae specimens were analyzed to 1) determine the species status of M. insularis and 2) to explore the relative intimacy of the relationship between M. insularis and Diaspididae. An analysis of molecular variance and the observed lack of association between clades and distinct habitats on the M. insularis phylogeny suggested that while M. insularis exhibits isolation by distance, it does not apparently diversify by habitat. When cryptic COI pseudogenes were accounted for, the majority of the genetic diversity exhibited by M. insularis was limited to a divergence of 3% or less suggesting that M. insularis represents a single, albeit broadly distributed, species. A cophylogenetic reconstruction of the relationship between M. insularis and Diaspididae yielded 14 “cospeciation” events but was not significant unlike reconstructions of host-parasite relationships. Analyses of reduced datasets suggested that incomplete taxon sampling may significantly affect cophylogenetic reconstruction results. / National Science Foundation (grants No. DEB-0072713, DEB-0344731 to BLF and DEB-0842395 to BLF and MAS), a Natural Sciences and Engineering Research Council of Canada Discovery Grant to MAS and a Leaders Opportunity Fund grant from the Canada Foundation for Innovation to MAS

Fluctuations in intracellular (Ca2+) calcium levels generate signaling events and regulate different cellular processes. Whilst the implication of Ca2+ in plant cell responses during arbuscular mycorrhiza (AM) interactions is well documented, nothing is known about the regulation or role of this secondary meesenger in the fungal symbiont. The molecular basis of fungal calcium homeostasis in the AM symbiosis was analyzed by investigating the expression of Ca2+-related fungal genes. In a first study, G. mosseae genes putatively encoding a MAP3k-like protein kinase (Gm2) and a P-type ATPase (Gm152) were investigated. Both Ca2+-related genes were up-regulated by A. sinicum root exudates, suggesting a role in early interactions prior to symbiosis establishment. The full-length cDNA sequence of Gm152 obtained from germinating spores of G. mosseae confirmed its identity. The role of Ca2+ in fungal processes leading to establishment of an AM symbiosis was investigated in more detail in G. intraradices-M. truncatula interactions. Enhanced expression of genes encoding six membrane transport proteins and one nuclear protein kinase, selected from the G. intraradices transcriptome database, was related to colonization of wild-type M. truncatula (line J5) roots and not observed with the mycorrhiza-resistant mutant dmi3/Mtsym13. Laser microdissection mapping of transcripts indicated that the Ca2+-related G. intraradices genes were differentially up-regulated in arbuscules and/or in intercellular hyphae. The tempo-spatial variations in fungal gene expression suggest different roles in the development or functioning of the AM symbiosis. Full-length cDNA of three G. intraradices genes putatively encoding a PMR-like endoplasmic reticulum P-type ATPase, a VCX1-like vacuolar Ca2+ ion transporter and a nuclear CCaMK were obtained for functional analyses in yeast mutants to gain insight into their role in the mycorrhizal symbiosis. Possible mechanisms are discussed in which Ca2+-related proteins of G. intraradices may play a role in the mobilization and perception of the intracellular messenger by the AM fungus during symbiotic interactions with host roots