M.A. / The dissemination of relevant information is of critical importance to the success of any organisation that aims at realising its corporate objectives and meeting the requirements of its stakeholders. The emergence of information and communication technologies (ITCs) has had a far-reaching impact on the relationship and power structure between organisations and their audiences, stakeholders and the media. It has become extremely difficult for organisations to define and segment these audiences as, for example, Internet audiences are widely spread across geographical, cultural and economic boundaries. This makes the packaging and dissemination of information a near Herculean task, as information needs to be generic enough to be commonly understood and accessed, yet personalised and customised in such a way that it still addresses the various audience segmentations effectively. The identification and profiling of target audiences, however, are critical for successful information dissemination too, as the information thus gained will guide communicators within organisations to compile relevant (to the specific target audiences) content and to package the information in such a way that it be best suited to the needs and resources of their target groups. Extensive market research should, therefore, be an integrated organisational activity that is performed on an ongoing basis and in a structured manner. The principal aim of this research project is to determine the extent to which information and communication technologies could enable the Alumni Office of the University of Johannesburg (as a newly merged institution) to disseminate information to its alumni effectively. This target audience consists mainly of the merged partners’ alumni groups, namely the RAU and TWR alumni, but also makes provision for the establishment of a third alumni affinity group in the foreseeable future, namely the alumni of the University of Johannesburg. The research consists of an in-depth literature review, followed by an empirical component. The purpose of the literature review is to create a theoretical framework in order to lay a solid foundation from which to conduct the empirical research. The various components of the research problem are discussed, as well as the variables that could possibly influence the outcome of the research. Next, the possible challenges facing the Alumni Office of the University of Johannesburg are investigated, with special emphasis on RAU and TWR alumni, as these two groups would (at least initially) form the basis of the alumni target audience of the University of Johannesburg. The various information and communication technologies that could be employed as information-dissemination tools by the Alumni Office of the University of Johannesburg in order to build and maintain valuable relationships with the alumni target audience are also explored. Following, the so-called “digital divide” is investigated, with an overview of the factors influencing this divide in South Africa, as well as the impact it may have on disseminating and sharing information to and with alumni of the University of Johannesburg. For the empirical study, the sample population for answering the quantitative, close-ended questionnaire by means of telephonic surveys was selected by means of stratified sampling from the RAU and TWR alumni databases respectively. Three hundred RAU alumni and three hundred TWR alumni were sampled from the total target-group population, of which 25% were males older than 35 years, 25% males 35 years and younger, 25% females older than 35 and 25% females 35 years and younger. The research results indicate that information and communication technologies could, to a large extent, enable the Alumni Office of the University of Johannesburg to disseminate information to its alumni effectively. In addition, it indicates that a total of 92.80% of respondents feel that contact between them and the Alumni Office would inspire greater loyalty towards the University. A majority of alumni (86.80%) indicated that they would like to receive information about the benefits to be derived from joining the Alumni Association of the University. A strong correlation exists between the establishment of an alumni benefits programme and the level of alumni involvement with the University. The research findings could provide the Alumni Office with valuable guidelines to plan and implement an interactive information-communication strategy by means of effective information dissemination, which could be to the mutual benefit of both the University and its alumni.

A maioria da população forma a sua opinião pelo senso comum, influenciada pelas informações divulgadas pela mídia, principalmente quando envolve acidentes. Normalmente, as notícias são veiculadas acentuando somente os seus aspectos negativos de forma dramática, o que em muito amplia o alcance espaço/temporal do impacto contrário de qualquer evento proveniente de ação antrópica, ou seja, não natural. Esse é o caso da Tecnologia Nuclear que, enquanto ciência e tecnologia, sofre as consequências decorrentes das duas bombas atômicas lançadas em 1945 sobre as cidades de Hiroshima e Nagasaki e dos acidentes com material radioativo. Até hoje, o público tem sérias restrições à sua utilização porque desconhece os benefícios que ela propicia para a sociedade, por terem a sua opinião formada pelo senso comum. Para o desenvolvimento da metodologia optou-se por trabalhar com grupos de professores como população amostral, haja vista que seus alunos são vetores para a disseminação do conhecimento adquirido em sala de aula, por serem profissionais críticos em relação às metodologias e aproximar a universidade aos profissionais de ensino. Este trabalho apresenta um roteiro de apresentação, como proposta para a divulgação da Tecnologia Nuclear para qualquer público, composta por cinco etapas: Questionário Inicial; Trecho de um Vídeo de uma reportagem do acidente com um aparelho de radioterapia; Palestra Elucidativa; Atividade Final e informações técnicas para Interação no Espaço da Tecnologia Nuclear. / Most of the people form their opinion through common sense, influenced by the information disclosed by the media, especially when it involves accidents. Usually, the news is conveyed accentuating only its negative aspects in a dramatic way, which greatly enlarges the space / time reach of the contrary impact of any event coming from anthropic action, that is, unnatural. This is the case of Nuclear Technology, which as science and technology, suffers from the consequences of the two atomic bombs launched in 1945 on the cities of Hiroshima and Nagasaki and from accidents with radioactive material. To this day, people have serious restrictions on its uses, because they are not aware of its benefits to the society, due to their common sense forget opinion. For the development of the methodology it was decided to work with groups of teachers as sample population, since their students are vectors for the dissemination of the knowledge acquired in the classroom, also because they are critical professionals in relation to methodologies and to bringing the university closer to education professionals. This work introduces a presentation screenplay as a proposal for the dissemination of Nuclear Technology to any public, composed of five stages: Initial Questionnaire; Video of news reporting the accident with a radiotherapy equipment; Elucidative Lecture; Final Activity and technic information to the Interaction in the Nuclear Technology Space.

A abordagem do tema mudanças climáticas por dois jornais diários e duas revistas semanais de informação em 2006 e 2007 e a percepção deste tema por formadores de opinião constituem o tema central deste trabalho. Uma pesquisa de campo foi realizada com assinantes dos jornais Folha de S. Paulo e O Estado de S. Paulo e das revistas Veja e Época, com jornalistas desses veículos e com cientistas da área de mudanças climáticas. Mostrou-se elevado o interesse do público pelos temas de ciência, em geral, e meio ambiente em particular. Nos periódicos analisados foram detectados conceitos incorretos do ponto de vista técnico e a cobertura voltou-se principalmente às pesquisas que mostravam impactos das mudanças climáticas. Segurança energética, outro fator fortemente relacionado à questão climática, orientou a pesquisa exploratória em busca de aferir a relação percebida pelo público entre mudanças climáticas e energia nuclear. Também pode ser traçado um paralelo entre o colapso ambiental e a catástrofe nuclear, presente no imaginário popular desde as explosões das bombas atômicas em Hiroshima e Nagasaki. Considerando o papel das ciências de modo geral, é imprescindível destacar que a melhor pesquisa não pode estar dissociada da comunicação eficiente e eficaz, capaz de mobilizar os cidadãos e sensibilizar tomadores de decisão. O diálogo entre cientistas e público, saberes tradicionalmente compartimentados, pode e deve ser praticado e a imprensa tem um papel fundamental neste processo. / The climate change approach by two daily newspapers and two weekly magazines in 2006 and 2007, and this theme perception by opinion-makers, constitute the major target of this work. A survey was conducted with subscribers to Folha de S. Paulo and O Estado de S. Paulo newspapers, Veja and Época magazines, with their journalists, as well as with climate change scientists. The survey showed that is equally high the public interest in general science subjects and in specific environmental themes. In the analyzed periodicals, some incorrect technical concepts were detected and the press coverage focused, mainly, on research into climate change impacts. Energy security, another factor strongly related to climate, was explored by the research to evaluate public view of a relation between climate change and nuclear energy. A parallel may be made between climate change and nuclear catastrophe, present in the popular imaginary, since the atomic bomb explosions in Hiroshima and Nagasaki. Considering the science role in general, it is essential to highlight the fact that the state of the art research should not be dissociated from efficient and effective communication, able to mobilize citizens and touch decision-makers. Although the dialogue between scientists and the public was considered, traditionally, as related to separated fields of awareness, it may be achieved and the media has a fundamental role in this process.

Os mecanismos responsáveis pelas manifestações hemorrágicas durante a leptospirose severa ainda são pouco compreendidos. Este trabalho avaliou os efeitos diretos e indiretos das leptospiras sobre moléculas do sistema de coagulação. Foi verificado que leptospiras virulentas são eficientes em bloquear a atividade da enzima trombina por meio do sequestro de seu sítio de ligação ao substrato, gerando uma menor formação do coágulo de fibrina, acarretando em sangramento e consequente disseminação do patógeno para outros sítios de infecção. Foi mostrado também que a inflamação causada pela resposta imune contra as bactérias causa uma ativação da coagulação, muito provavelmente via expressão de Fator Tissular, o que ocasiona um consumo e consequente esgotamento dos fatores e inibidores de coagulação, culminando em hemorragia e formação de trombos, os quais podem levar à falência de órgãos. Estes resultados melhoram o entendimento da patogênese da leptospirose e podem favorecer o desenvolvimento de terapias para as manifestações hemorrágicas. / The mechanisms responsible for the hemorrhagic manifestations during severe leptospirosis are still poorly understood. This work evaluated the direct and indirect effects of leptospires upon molecules of the coagulation system. It has been shown that virulent leptospires are effective in blocking the activity of the enzyme thrombin by sequestration of its substrate binding site, generating less fibrin clot formation, leading to bleeding and consequent dissemination of the pathogen to other sites of infection. It has also been shown that the inflammation caused by the immune response against the bacteria causes an activation of the coagulation, most probably via expression of Tissue Factor, which causes a consumption and consequent depletion of coagulation factors and inhibitors, culminating in hemorrhage and thrombus formation, which can lead to organ failure. These results improve the understanding of the pathogenesis of leptospirosis and may favor the development of therapies for hemorrhagic manifestations.

A maioria da população forma a sua opinião pelo senso comum, influenciada pelas informações divulgadas pela mídia, principalmente quando envolve acidentes. Normalmente, as notícias são veiculadas acentuando somente os seus aspectos negativos de forma dramática, o que em muito amplia o alcance espaço/temporal do impacto contrário de qualquer evento proveniente de ação antrópica, ou seja, não natural. Esse é o caso da Tecnologia Nuclear que, enquanto ciência e tecnologia, sofre as consequências decorrentes das duas bombas atômicas lançadas em 1945 sobre as cidades de Hiroshima e Nagasaki e dos acidentes com material radioativo. Até hoje, o público tem sérias restrições à sua utilização porque desconhece os benefícios que ela propicia para a sociedade, por terem a sua opinião formada pelo senso comum. Para o desenvolvimento da metodologia optou-se por trabalhar com grupos de professores como população amostral, haja vista que seus alunos são vetores para a disseminação do conhecimento adquirido em sala de aula, por serem profissionais críticos em relação às metodologias e aproximar a universidade aos profissionais de ensino. Este trabalho apresenta um roteiro de apresentação, como proposta para a divulgação da Tecnologia Nuclear para qualquer público, composta por cinco etapas: Questionário Inicial; Trecho de um Vídeo de uma reportagem do acidente com um aparelho de radioterapia; Palestra Elucidativa; Atividade Final e informações técnicas para Interação no Espaço da Tecnologia Nuclear. / Most of the people form their opinion through common sense, influenced by the information disclosed by the media, especially when it involves accidents. Usually, the news is conveyed accentuating only its negative aspects in a dramatic way, which greatly enlarges the space / time reach of the contrary impact of any event coming from anthropic action, that is, unnatural. This is the case of Nuclear Technology, which as science and technology, suffers from the consequences of the two atomic bombs launched in 1945 on the cities of Hiroshima and Nagasaki and from accidents with radioactive material. To this day, people have serious restrictions on its uses, because they are not aware of its benefits to the society, due to their common sense forget opinion. For the development of the methodology it was decided to work with groups of teachers as sample population, since their students are vectors for the dissemination of the knowledge acquired in the classroom, also because they are critical professionals in relation to methodologies and to bringing the university closer to education professionals. This work introduces a presentation screenplay as a proposal for the dissemination of Nuclear Technology to any public, composed of five stages: Initial Questionnaire; Video of news reporting the accident with a radiotherapy equipment; Elucidative Lecture; Final Activity and technic information to the Interaction in the Nuclear Technology Space.

Numerous local incidents occur on road networks daily many of which may lead to congestion and safety hazards. If vehicles can be provided with information about such incidents or traffic conditions in advance, the quality of driving in terms of time, distance, and safety can be improved significantly. Vehicular Ad Hoc Networks (VANETs) have recently emerged as an effective tool for improving road safety through the propagation of warning messages among the vehicles in the network about potential obstacles on the road ahead. This research has presented an effective warning data dissemination scheme which deploys relay strategy and concept of Region of Interest (RoI). A warning data message is characterized as spatio-temporal, implying that both the location and the time of an incident must be considered. Factors such as the type of warning message, the layout of the road network, the traffic density and the capacity of alternative roads are influential in determining the RoI in which the warning message needs to be propagated. In the developed scheme, the type of warning message is taken into account for the determination of the RoI so that the more severe the incident, the wider the RoI. In the selection of the relay point, the border relay area in which the relay point is placed, is adapted to the traffic density so that the higher the traffic density , the narrower the relay area. Traffic statistics are used to calculate the RoI, which is then enclosed in the warning message so that the message is not retransmitted beyond the RoI. Also, the responsibility for retransmitting the message is assigned to the relay node. The data is then disseminated effectively so that vehicles in areas unrelated to the incident are not informed. The primary objective of this research is to provide better understanding of the dissemination of warning data in the context of a vehicular network with the ultimate goal of increasing the possibility of using VANETs for safety applications.

Numerous local incidents occur on road networks daily many of which may lead to congestion and safety hazards. If vehicles can be provided with information about such incidents or traffic conditions in advance, the quality of driving in terms of time, distance, and safety can be improved significantly. Vehicular Ad Hoc Networks (VANETs) have recently emerged as an effective tool for improving road safety through the propagation of warning messages among the vehicles in the network about potential obstacles on the road ahead. This research has presented an effective warning data dissemination scheme which deploys relay strategy and concept of Region of Interest (RoI). A warning data message is characterized as spatio-temporal, implying that both the location and the time of an incident must be considered. Factors such as the type of warning message, the layout of the road network, the traffic density and the capacity of alternative roads are influential in determining the RoI in which the warning message needs to be propagated. In the developed scheme, the type of warning message is taken into account for the determination of the RoI so that the more severe the incident, the wider the RoI. In the selection of the relay point, the border relay area in which the relay point is placed, is adapted to the traffic density so that the higher the traffic density , the narrower the relay area. Traffic statistics are used to calculate the RoI, which is then enclosed in the warning message so that the message is not retransmitted beyond the RoI. Also, the responsibility for retransmitting the message is assigned to the relay node. The data is then disseminated effectively so that vehicles in areas unrelated to the incident are not informed. The primary objective of this research is to provide better understanding of the dissemination of warning data in the context of a vehicular network with the ultimate goal of increasing the possibility of using VANETs for safety applications.

<p>With the advent of Web 2.0 and the Digital Age, we are witnessing an unprecedented increase in the amount of information collected, and in the number of users interested in different types of information. This growth means that traditional techniques, where users poll data sources for information of interest, are no longer sufficient. Polling too frequently does not scale, while polling less often may result in users missing important updates. The alternative push technology has long been the goal of publish/subscribe systems, which proactively push updates (events) to users with matching interests (expressed as subscriptions). The push model is better suited for ensuring scalability and timely delivery of updates, important in many application domains: personal (e.g., RSS feeds, online auctions), financial (e.g., portfolio monitoring), security (e.g., reporting network anomalies), etc.</p><p>Early publish/subscribe systems were based on predefined subjects (channels), and were too coarse-grained to meet the specific interests of different subscribers. The second generation of content-based publish/subscribe systems offer greater flexibility by supporting subscriptions defined as predicates over message contents. However, subscriptions are still stateless filters over individual messages, so they cannot express queries across different messages or over the event history. The few systems that support more powerful database-style subscriptions do not address the problem of efficiently delivering updates to a large number of subscribers over a wide-area network. Thus, there is a need to develop next-generation publish/subscribe systems that unify the support for richer database-style subscription queries and flexible wide-area notification. This support needs to be complemented with robust processing and dissemination techniques that scale to high event rates and large databases, as well as to a large number of subscribers over the Internet.</p><p>The main contribution of our work is a collection of techniques to support efficient and scalable event processing and notification dissemination for an Internet-scale publish/subscribe system with a rich subscription model. We investigate the interface between event processing by a database server and notification delivery by a dissemination network. Previous research in publish/subscribe has largely been compartmentalized; database-centric and network-centric approaches each have their own limitations, and simply putting them together does not lead to an efficient solution. A closer examination of database/network interfaces yields a spectrum of new and interesting possibilities. In particular, we propose message and subscription reformulation as general techniques to support stateful subscriptions over existing content-driven networks, by converting them into equivalent but stateless forms. We show how reformulation can successfully be applied to various stateful subscriptions including range-aggregation, select-joins, and subscriptions with value-based notification conditions. These techniques often provide orders-of-magnitude improvement over simpler techniques adopted by current systems, and are shown to scale to millions of subscriptions. Further, the use of a standard off-the-shelf content-driven dissemination interface allows these techniques to be easily deployed, managed, and maintained in a large-scale system.</p><p>Based on our findings, we have built a high-performance publish/subscribe system named ProSem (to signify the inseparability of database processing and network dissemination). ProSem uses our novel techniques for group-processing many types of complex and expressive subscriptions, with a per-event optimization framework that chooses the best processing and dissemination strategy at runtime based on online statistics and system objectives.</p> / Dissertation

As computers become pervasive in environments that include the home and community, new applications are emerging that will create and manipulate sensitive and private information. These applications span systems ranging from personal to mobile and hand held devices. They would benefit from a data storage service that protects the integrity and confidentiality of the stored data and is highly available. Such a data repository would have to meet the needs of a variety of applications, handling data with varying security and performance requirements. Providing simultaneously both high levels of security and high levels of performance may not be possible when many nodes in the system are under attack. The agility approach to building secure distributed services advocates the principle that the overhead of providing strong security guarantees should be incurred only by those applications that require such high levels of security and only at times when it is necessary to defend against high threat levels. A storage service that is designed for a variety of applications must follow the principles of agility, offering applications a range of options to choose from for their security and performance requirements. This research presents secure store, a secure and highly available distributed store to meet the performance and security needs of a variety of applications. Secure store is designed to guarantee integrity, confidentiality and availability of stored data even in the face of limited number of compromised servers. Secure store is designed based on the principles of agility. Secure store integrates two well known techniques, namely replication and secret-sharing, and exploits the tradeoffs that exist between security and performance to offer applications a range of options to choose from to suit their needs. This thesis makes several contributions, including (1) illustration of the the principles of agility, (2) a novel gossip-style secure dissemination protocol whose performance is comparable to the best-possible benign-case protocol in the absence of any malicious activity, (3) demonstration of the performance benefits of using weaker consistency models for data access, and (4) a technique called collective endorsement that can be used in other secure distributed applications.

Based on previous evidence that there are information heterogeneities in capital markets, three essays including empirical frameworks for examining the information processes that impact portfolio investments and corporate investments was proposed. The first essay considers information channels among mutual fund managers (fund-fund networks), and between holding companies and fund managers (fund-company networks). Results show that (1) fund-fund (fund-company) information networks help in generating positive risk-adjusted returns from holdings in absence of fund-company (fund-fund) networks; (2) fund-company networks create information advantage only when the networks are relatively exclusive. Superior networks seem to pick stocks which outperform beyond the quarter. The second essay examines mutual fund managers tendency to deviate from the strategies of their peers. Results indicate a significantly negative relationship between the managers deviating tendency and fund performance, suggesting that the average fund manager is more likely to make erroneous decisions when they deviate from their peers. The third essay investigates the determinants of target choices in corporate acquisitions. Results reveal the influence of various factors, including information asymmetries, which may drive this behavior, including economic opportunities, anti-takeover regimes, competitive responses to other managers, and acquirers size and book-to-market ratios.