892 resultados para Anti Infective Agents


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Chlamydia trachomatis is a significant human pathogen with potentially severe disease sequelae in the genital tract, including infertility. A successful vaccine will need to effectively target immunity to the genital mucosa. Intranasal immunisation with cholera toxin (CT) can target immunity to the genital tract, but has the potential to cause neurological side effects. CTA1-DD is a non-toxic potent mucosal adjuvant which combines the enzymatic properties of CT, with a B cell targeting moiety. Here, we demonstrate that intranasal immunisation with CTA1-DD and chlamydial Major Outer Membrane Protein (MOMP) results in the induction of neutralising systemic and mucosal antibodies, and reduces the level of chlamydial shedding following intravaginal challenge with Chlamydia muridarum. Thus, CTA1-DD is an effective adjuvant for vaccine development against Chlamydia trachomatis, and possibly also a range of other genital pathogens.

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Distributed Denial of Services DDoS, attacks has become one of the biggest threats for resources over Internet. Purpose of these attacks is to make servers deny from providing services to legitimate users. These attacks are also used for occupying media bandwidth. Currently intrusion detection systems can just detect the attacks but cannot prevent / track the location of intruders. Some schemes also prevent the attacks by simply discarding attack packets, which saves victim from attack, but still network bandwidth is wasted. In our opinion, DDoS requires a distributed solution to save wastage of resources. The paper, presents a system that helps us not only in detecting such attacks but also helps in tracing and blocking (to save the bandwidth as well) the multiple intruders using Intelligent Software Agents. The system gives dynamic response and can be integrated with the existing network defense systems without disturbing existing Internet model. We have implemented an agent based networking monitoring system in this regard.

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Streptococcus pyogenes, also known as Group A Streptococcus (GAS) has been associated with a range of diseases from the mild pharyngitis and pyoderma to more severe invasive infections such as streptococcal toxic shock. GAS also causes a number of non-suppurative post-infectious diseases such as rheumatic fever, rheumatic heart disease and glomerulonephritis. The large extent of GAS disease burden necessitates the need for a prophylactic vaccine that could target the diverse GAS emm types circulating globally. Anti-GAS vaccine strategies have focused primarily on the GAS M-protein, an extracellular virulence factor anchored to GAS cell wall. As opposed to the hypervariable N-terminal region, the C-terminal portion of the protein is highly conserved among different GAS emm types and is the focus of a leading GAS vaccine candidate, J8-DT/alum. The vaccine candidate J8-DT/alum was shown to be immunogenic in mice, rabbits and the non-human primates, hamadryas baboons. Similar responses to J8-DT/alum were observed after subcutaneous and intramuscular immunization with J8-DT/alum, in mice and in rabbits. Further assessment of parameters that may influence the immunogenicity of J8-DT demonstrated that the immune responses were identical in male and female mice and the use of alum as an adjuvant in the vaccine formulation significantly increased its immunogenicity, resulting in a long-lived serum IgG response. Contrary to the previous findings, the data in this thesis indicates that a primary immunization with J8-DT/alum (50ƒÊg) followed by a single boost is sufficient to generate a robust immune response in mice. As expected, the IgG response to J8- DT/alum was a Th2 type response consisting predominantly of the isotype IgG1 accompanied by lower levels of IgG2a. Intramuscular vaccination of rabbits with J8-DT/alum demonstrated that an increase in the dose of J8-DT/alum up to 500ƒÊg does not have an impact on the serum IgG titers achieved. Similar to the immune response in mice, immunization with J8-DT/alum in baboons also established that a 60ƒÊg dose compared to either 30ƒÊg or 120ƒÊg was sufficient to generate a robust immune response. Interestingly, mucosal infection of naive baboons with a M1 GAS strain did not induce a J8-specific serum IgG response. As J8-DT/alum mediated protection has been previously reported to be due to the J8- specific antibody formed, the efficacy of J8-DT antibodies was determined in vitro and in vivo. In vitro opsonization and in vivo passive transfer confirmed the protective potential of J8-DT antibodies. A reduction in the bacterial burden after challenge with a bioluminescent M49 GAS strain in mice that were passively administered J8-DT IgG established that protection due to J8-DT was mediated by antibodies. The GAS burden in infected mice was monitored using bioluminescent imaging in addition to traditional CFU assays. Bioluminescent GAS strains including the ‘rheumatogenic’ M1 GAS could not be generated due to limitations with transformation of GAS, however, a M49 GAS strain was utilized during BLI. The M49 serotype is traditionally a ‘nephritogenic’ serotype associated with post-streptococcal glomerulonephritis. Anti- J8-DT antibodies now have been shown to be protective against multiple GAS strains such as M49 and M1. This study evaluated the immunogenicity of J8-DT/alum in different species of experimental animals in preparation for phase I human clinical trials and provided the ground work for the development of a rapid non-invasive assay for evaluation of vaccine candidates.

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The ultimate goal of an authorisation system is to allocate each user the level of access they need to complete their job - no more and no less. This proves to be challenging in an organisational setting because on one hand employees need enough access to perform their tasks, while on the other hand more access will bring about an increasing risk of misuse - either intentionally, where an employee uses the access for personal benefit, or unintentionally through carelessness, losing the information or being socially engineered to give access to an adversary. With the goal of developing a more dynamic authorisation model, we have adopted a game theoretic framework to reason about the factors that may affect users’ likelihood to misuse a permission at the time of an access decision. Game theory provides a useful but previously ignored perspective in authorisation theory: the notion of the user as a self-interested player who selects among a range of possible actions depending on their pay-offs.

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The ‘anti- of ‘(Anti)Queer’ is a queer anti. In particle physics, a domain of science which was for a long time peddled as ultimately knowable, rational and objective, the postmodern turn has made everything queer (or chaotic, as the scientific version of this turn is perhaps more commonly named). This is a world where not only do two wrongs not make a right, but a negative and positive do not calmly cancel each other out to leave nothing, as mathematics might suggest. When matter meets with anti-matter, the resulting explosion can produce not only energy - heat and light? - but new matter. We live in a world whose very basics are no longer the electron and the positron, but an ever proliferating number of chaotic, unpredictable - queer? - subatomic particles. Some are ‘charmed’, others merely ‘strange’ . Weird science indeed. The ‘Anti-’ of ‘Anti-queer’ does not place itself neatly into binaries. This is not a refutation of all that queer has been or will be. It is explicitly a confrontation, a challenge, an attempt to take seriously not only the claims made for queer but the potent contradictions and silences which stand proudly when any attempt is made to write a history of the term. Specifically, ‘Anti-Queer’ is not Beyond Queer, the title of Bruce Bawer’s 1996 book which calmly and self-confidently explains the failings of queer, extols a return to a liberal political theory of cultural change and places its own marker on queer as a movement whose purpose has been served. We are not Beyond Queer. And if we are Anti-Queer, it is only to challenge those working in the arena to acknowledge and work with some of the facts of the movement’s history whose productivity has been erased with a gesture which has, proved, bizarrely, to be reductive and homogenising.

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Intelligent agents are an advanced technology utilized in Web Intelligence. When searching information from a distributed Web environment, information is retrieved by multi-agents on the client site and fused on the broker site. The current information fusion techniques rely on cooperation of agents to provide statistics. Such techniques are computationally expensive and unrealistic in the real world. In this paper, we introduce a model that uses a world ontology constructed from the Dewey Decimal Classification to acquire user profiles. By search using specific and exhaustive user profiles, information fusion techniques no longer rely on the statistics provided by agents. The model has been successfully evaluated using the large INEX data set simulating the distributed Web environment.