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Clostridium difficile-associated diarrhoea (CDAD) is a frequently occurring healthcare-associated infection, which is responsible for significant morbidity and mortality amongst elderly patients in healthcare facilities. Environmental contamination is known to play an important contributory role in the spread of CDAD and it is suspected that contamination might be occurring as a result of aerial dissemination of C. difficile spores. However previous studies have failed to isolate C. difficile from air in hospitals. In an attempt to clarify this issue we undertook a short controlled pilot study in an elderly care ward with the aim of culturing C. difficile from the air. In a survey undertaken during February (two days) 2006 and March (two days) 2007, air samples were collected using a portable cyclone sampler and surface samples collected using contact plates in a UK hospital. Sampling took place in a six bedded elderly care bay (Study) during February 2006 and in March 2007 both the study bay and a four bedded orthopaedic bay (Control). Particulate material from the air was collected in Ringer's solution, alcohol shocked and plated out in triplicate onto Brazier's CCEY agar without egg yolk, but supplemented with 5 mg/L of lysozyme. After incubation, the identity of isolates was confirmed by standard techniques. Ribotyping and REP-PCR fingerprinting were used to further characterise isolates. On both days in February 2006, C. difficile was cultured from the air with 23 samples yielding the bacterium (mean counts 53 ¿ 426 cfu/m3 of air). One representative isolate from each of these was characterized further. Of the 23 isolates, 22 were ribotype 001 and were indistinguishable on REP-PCR typing. C. difficile was not cultured from the air or surfaces of either hospital bay during the two days in March 2007. This pilot study produced clear evidence of sporadic aerial dissemination of spores of a clone of C. difficile, a finding which may help to explain why CDAD is so persistent within hospitals and difficult to eradicate. Although preliminary, the findings reinforce concerns that current C. difficile control measures may be inadequate and suggest that improved ward ventilation may help to reduce the spread of CDAD in healthcare facilities.

This writing is an experiment in combining the two most important frameworks through which I understand the world, the storytelling traditions of my people, the Mvskoke(Creek), and the rational tradition that began with European Enlightenment era thinking. By weaving allegorical narrative (much of it personal) into theoretical speculation, I draw connections between recollection, truth, and the act of making. This examination of the gaps and connections between seemingly disparate worldviews, runs in parallel to the purpose of my work, wherein I construct fictive symbiotic and parasitic relationships between jewelry and wearer. This work takes advantage of the wearer as environment, resource, and propagator. By abstracting from real-world biological structures, this work conflates genetic and memetic dissemination. I am creating systems and models of systems using individual jewelry pieces for specific wearers that reflect the structure of arrangements that are repeated throughout nature. Ultimately I am raising questions about the hard lines that we draw between things in nature—including ourselves—and our place in biological, cultural, and personal systems.

This thesis addresses the concept and forms of dissemination in political communication and news media. It investigates the new age of dissemination of global communication manifested in a new relationship between political communication and media systems. The broad aim of this project is to investigate the ‘media reality’ of political communication in this new age of dissemination. Working within the sphere of political communication and interconnected media systems, the thesis examines how the information in news source texts and responses to them is recontextualised and disseminated worldwide, and fed back again through recursive communication. Specifically, the thesis also considers ways in which the aims of the political phenomenon of Hezbollah are disseminated and connected across various news media outlets. In particular, the process of recursive dissemination of communication is analysed in three news media outlets, namely Al-Jazeera, the BBC, and CNN. The project has three principal conceptual building blocks: dissemination, political communication, and discourse and intertexts. The theoretical framework has determined the methods used to undertake a qualitative analysis of the data. Discourse analysis is used to consider intertexts and sub-texts, legitimation processes, framing, representation, and schematisation in the data. These dimensions are highly useful tools in identifying shifts across the three media organisations. This thesis has three specific objectives. Its first aim is to reconceptualise communication, establish a communicative model characterised by recursivity (one in which political communication and media systems play back on each other in feedback and feed-forward loops, which add intensity), and show how recursivity has gained in importance in the context of mass mediatisation, bringing about a new age of dissemination. That is, the political messages of Hassan Nasrallah, which polarise representations, are recontextualised and disseminated across media contexts in complex processes involving recursive media interplays. These processes have a direct link with the historical context in the sense that political communication and media systems play back on each other in feedback and feed-forward loops. The second aim is to investigate the appropriate approaches for the study of that communication in terms of the relationship between intertextuality, discourse, ideology as belief systems, framings, and competing framings which create new realities; this connects well with the conceptual framework of recursivity and dissemination. The third aim is to achieve in the data analysis a more sophisticated understanding of Hezbollah as a highly significant political actor, by creating a multicontextual analysis of recursive framing. The thesis demonstrates the complexity of recursivity and dissemination of political communication. It sets out to improve our understanding both of Hezbollah and of the politics the Middle East. The core of this thesis lies in its concern in reconceptualising political communication and applying it to the analysis of Nasrallah’s speeches and their recontextualisation in the above three global media organisations.

The avalanche of data from scientific instruments and the ensuing interest from geographically distributed users to analyze and interpret it accentuates the need for efficient data dissemination. An optimal data distribution scheme will find the delicate balance between conflicting requirements of minimizing transfer times, minimizing the impact on the network, and uniformly distributing load among participants. We identify several data distribution techniques, some successfully employed by today's peer-to-peer networks: staging, data partitioning, orthogonal bandwidth exploitation, and combinations of the above. We use simulations to explore the performance of these techniques in contexts similar to those used by today's data-centric scientific collaborations and derive several recommendations for efficient data dissemination. Our experimental results show that the peer-to-peer solutions that offer load balancing and good fault tolerance properties and have embedded participation incentives lead to unjustified costs in today's scientific data collaborations deployed on over-provisioned network cores. However, as user communities grow and these deployments scale, peer-to-peer data delivery mechanisms will likely outperform other techniques.

As broadband connections to the Internet become more common, new information sharing applications that provide rich services to distributed users will emerge. Furthermore, as computing devices become pervasive and better connected, the scalability requirements for Internet-based services are also increasing. Distributed object middleware has been widely used to develop such applications since it made it easier to rapidly develop distributed applications for heterogeneous computing and communication systems. As the application's scale increases, however, the client/server architecture limits the performance due to the bottleneck at the centralized servers. The recent development in peer-to-peer technologies creates a new opportunity for addressing scalability and performance problems for services that are used by many nodes. In a peer-to-peer system, peer nodes can contribute a fraction of their resources to the system, enabling more flexible and extended sharing between the entities in the system. When peer nodes are required to contribute their resources by replicating a service for self and others, however, several new challenges arise. Our thesis is that non-dedicated resources in a distributed system can be utilized to replicate shared objects dynamically so that the quality and scalability of a distributed service can be achieved with lower cost by replicating the objects at right places and updates to those shared objects can be disseminated efficiently and quickly. The following are the contributions of our work that has been done to validate the thesis. 1. A new fair and self-managing replication algorithm that allows distributed non-dedicated resources to be used to improve service performance with lower cost. 2. A multicast grouping algorithm that is used to disseminate updates to the shared objects among a large set of heterogeneous peer nodes to keep consistent view for all peer nodes. It groups nodes with similar interests into same group and multicasts all the required data to the group so that the unwanted data received by each node can be minimized. 3. An overlay construction algorithm that aims at reducing both network latency and total network traffic when delivering data through the built overlay network. 4. An implementation of a distributed object framework, GT-RMI, that allows peer nodes to invoke dynamically replicated objects transparently. The framework can be configured for a particular peer node through a policy file.

The avalanche of data from scientific instruments and the ensuing interest from geographically distributed users to analyze and interpret it accentuates the need for efficient data dissemination. An optimal data distribution scheme will find the delicate balance between conflicting requirements of minimizing transfer times, minimizing the impact on the network, and uniformly distributing load among participants. We identify several data distribution techniques, some successfully employed by today's peer-to-peer networks: staging, data partitioning, orthogonal bandwidth exploitation, and combinations of the above. We use simulations to explore the performance of these techniques in contexts similar to those used by today's data-centric scientific collaborations and derive several recommendations for efficient data dissemination. Our experimental results show that the peer-to-peer solutions that offer load balancing and good fault tolerance properties and have embedded participation incentives lead to unjustified costs in today's scientific data collaborations deployed on over-provisioned network cores. However, as user communities grow and these deployments scale, peer-to-peer data delivery mechanisms will likely outperform other techniques.

This study investigates the role of the business press in disseminating management earnings guidance news to capital market participants. Using a unique sample of over 55,000 articles that relate specifically to management guidance, I find that 48 percent of all guidance receives coverage in the business press, with substantial within-firm variation. I then identify firm and guidance characteristics that are associated with the likelihood that guidance receives press coverage. Controlling for the endogeneity of press coverage, I find that dissemination in the press has a significant impact on the market reaction to guidance, and this effect is economically large. This study is the first to provide evidence that there is systematic variation in the extent to which guidance news is disseminated through the press, and that this variation has a significant effect on the market consequences of guidance.

Access to modern energy is essential to achieve sustainable development and poverty reduction. However, with about 321 kWh per capita, Rwanda is ranked among the countries that have a lower consumption of primary energy in the world. More than 86 percent of its total energy comes from the traditional biomass energy such as forests, agricultural residues and by-products from crops that lead to environmental degradation and ecological imbalance and negative impacts on human health as well. In addition, only 301,500 ha of forest are available for fuel wood and other uses such as construction for a total population of 10.5 million. Therefore, decentralized energy sources in small-scale are presented to improve access to "appropriate" energy, which are beneficial to human health and environmental perspectives. The anaerobic digestion of biomass, popularly called “biogas”, is one of the appropriate energy technologies for cooking and/or lighting purposes (both in households and in institutions), which receives special attention in Rwanda since 2007. Three main objectives of this study were to assess the current biogas sector in Rwanda, to make projections of biogas development by 2020 and finally to analyze the socio-economic and environment benefits of biogas use to the Rwandan community. The fieldwork conducted in two districts per province in addition to services that are in the capital, was based on the structured questionnaire, discussion with key people and see the state of biogas built. Therefore, in this study we used the "Appropriate Energy Model” to measure the degree of biogas dissemination, which educates for “geographical, institutional, entrepreneurial and socio-cultural “aspects. The results showed that the temperature conditions in the country are generally conducive to the operation of a digester. However, the drought period between June and August, water scarcity in some regions and a low potential for digester feeding impede the propagation of biogas to a large number of people.  The Rwandan entrepreneurs do not face institutional barriers to start-up biogas companies since the bureaucratic system in registration of a company is transparent. The installation costs of biogas plant are so high that they hamper the dissemination of biogas; however biogas technology does not contradict the socio-cultural conditions of Rwandans. Based on projections of potential biogas in Rwanda in 2020, following three scenarios for 2020 biogas development were identified: 1,135,000 biogas plants can be built in 2020 by considering a global basis the potential biogas available If 70% of the population will live in grouped settlements in 2020, 70% of Rwandan households will use biogas if additional resources as livestock and subsidies were provided to the poor families. Only 10% of the population (251,000households) will be eligible for biogas installation Reducing the consumption of firewood after biogas operation provides annual coverage of approximately 0.306 ha of forest area per household. Therefore, each household biogas would reduce annual GHG emissions of about 4.1 tonnes of CO2 and could possibly lead to Rwanda an annual income of about USD 21 due to the reduction of CO2 emissions in a hypothetical rate USD 5 per ton of CO2 if registered under the CDM.

The avalanche of data from scientific instruments and the ensuing interest from geographically distributed users to analyze and interpret it accentuates the need for efficient data dissemination. An optimal data distribution scheme will find the delicate balance between conflicting requirements of minimizing transfer times, minimizing the impact on the network, and uniformly distributing load among participants. We identify several data distribution techniques, some successfully employed by today's peer-to-peer networks: staging, data partitioning, orthogonal bandwidth exploitation, and combinations of the above. We use simulations to explore the performance of these techniques in contexts similar to those used by today's data-centric scientific collaborations and derive several recommendations for efficient data dissemination. Our experimental results show that the peer-to-peer solutions that offer load balancing and good fault tolerance properties and have embedded participation incentives lead to unjustified costs in today's scientific data collaborations deployed on over-provisioned network cores. However, as user communities grow and these deployments scale, peer-to-peer data delivery mechanisms will likely outperform other techniques. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate