Where there’s smoke, there’s more smoke: The social settings and friendship interactions that encourage young adults to smoke cigarettes

Despite widespread public health campaigns in Western countries people continue to smoke cigarettes and more worryingly, young people continue to take up the habit. In this thesis it is argued that cigarette smoking practices for young adults can be understood in terms of contributing to their sense of identity construction through friendship interactions and sociability. Data collected from email administered surveys and snowball sampling techniques, alongside secondary data from the National Drug Strategy Household Survey (2007), inform the research undertaken in this thesis and the results support the social benefits hypothesis in explaining why young adults smoke cigarettes. This study thereby suggests that in order for anti-smoking initiatives to be more successful in tackling the smoking habits of young adults additional research is required in identity formation, interactive factors and sociability factors that affect cigarette smoking practices of young adults

Discourse Semantics for the Analysis of Change in Language

This paper purports to elaborate and address several issues which lie at the intersection of computational linguistics and psychology. The first issue addressed is that of the interaction between discourse and semantics by virtue of empirical linguistic and psychotherapeutic evidence. This paper then gives a formal account of the knowledge representation and reasoning processes involved in the construction of an XML knowledge base for use in the sematic analysis of psychotherapeutic transcripts. Computational methods for the automatic mark-up and inference of the psychotherapeutic phenomena under investigation are detailed in order to further develop intuitions behind a particular pragmatic theory of language known as the Metamodel. The work presented here ultimately aims to produce a sustainable system for the evaluation of the effectiveness of any given psychotherapeutic technique. The possibility exists for such a system to recognise successful therapeutic mechanisms and further still, to infer new ones, or suggest improvements, or offer novel explanations as to the success or failure of the therapy itself. The work discussed here stems from research in computational linguistics, psychotherapy, and philosophy. The corpus used is a culmination of client transcripts taken before, during, and after therapy. The particular therapeutic technique used here is known as the Metamodel (Bandler and Grinder, 1975). The Metamodel was originally proffered as a method of language analysis suitable for use by practitioners of any psychotherapeutic technique. It theorises that speech utterances are related to a clients deep structure through three primary mechanisms, namely generalisation, deletion, and distortion. Previous hand tagging of our data has proven support for such claims. It is our aim to automate the identification and reasoning process. The issues and processes involved in the automation of such tagging are discussed here. Architectural and philosophical issues relating syntax (or grammar), semantics (Larson and Segal, 1995), and pragmatics (Grice, 1989; Searle, 1969) are raised. Discourse Representation Theory (Kamp, 1981; Asher and Lascarides, 1995) is discussed and used here in order to infer discourse relations.Hosted by the Scholarly Text and Imaging Service (SETIS), the University of Sydney Library, and the Research Institute for Humanities and Social Sciences (RIHSS), the University of Sydney

Leukocytes in a Plasmodium falciparum-infected blood meal reduce transmission of Malaria to Anopheles mosquitoes.

Contains fulltext : 26197___.PDF (publisher's version ) (Open Access

Clinical outcome of experimental human malaria induced by Plasmodium falciparum-infected mosquitoes.

Contains fulltext : 47503.pdf (publisher's version ) (Open Access)BACKGROUND: Human experimental malaria infections have been safely carried out previously. The objective of this study was to evaluate infection rates and clinical safety of different protocols for human experimental malaria induced by Plasmodium falciparum-infected mosquitoes. METHODS: Thirty nonimmune volunteers were infected by bites of 1-2 or 4-7 Anopheles stephensi mosquitoes infected with the NF54 strain of P. falciparum. RESULTS: A 100 or 50% infection rate was obtained after bites of 4-7 and 1-2 infected mosquitoes, respectively. Median prepatent period was 8.8 days. The most common symptoms after a median incubation time of eight days were headache, malaise/fatigue and fever. There was no significant difference in clinical and parasitological presentation between groups infected by 4-7 or 1-2 mosquitoes. Delay of treatment by maximally 48 hours after the first positive thick smear was generally well tolerated but fever was higher and more frequently observed. The most prominent laboratory abnormality was uncomplicated thrombocytopenia. Two volunteers with parasitaemia developed psychiatric side effects after chloroquine treatment. CONCLUSION: With stringent inclusion criteria, close monitoring and immediate administration of treatment upon detection of parasitaemia, experimental human malaria challenges can be considered safe and generally well tolerated

Molecular detection and quantification of Plasmodium falciparum-infected human hepatocytes in chimeric immune-deficient mice.

Contains fulltext : 125669.pdf (publisher's version ) (Open Access

A semi-automated luminescence based standard membrane feeding assay identifies novel small molecules that inhibit transmission of malaria parasites by mosquitoes.

Contains fulltext : 152284.pdf (publisher's version ) (Open Access

Sporozoite immunization of human volunteers under chemoprophylaxis induces functional antibodies against pre-erythrocytic stages of Plasmodium falciparum

Contains fulltext : 136852.pdf (publisher's version ) (Open Access)BACKGROUND: Long-lasting and sterile protective immunity against Plasmodium falciparum can be achieved by immunization of malaria-naive human volunteers under chloroquine prophylaxis with sporozoites delivered by mosquito bites (CPS-immunization). Protection is mediated by sporozoite/liver-stage immunity. In this study, the capacity of CPS-induced antibodies to interfere with sporozoite functionality and development was explored. METHODS: IgG was purified from plasma samples obtained before and after CPS-immunization from two separate clinical trials. The functionality of these antibodies was assessed in vitro in gliding and human hepatocyte traversal assays, and in vivo in a human liver-chimeric mouse model. RESULTS: Whereas pre-treatment of sporozoites with 2 mg/ml IgG in the majority of the volunteers did not have an effect on in vitro sporozoite gliding motility, CPS-induced IgG showed a distinct inhibitory effect in the sporozoite in vitro traversal assay. Pre-treatment of P. falciparum sporozoites with post-immunization IgG significantly inhibited sporozoite traversal through hepatocytes in 9/9 samples when using 10 and 1 mg/ml IgG, and was dose-dependent, resulting in an average 16% and 37% reduction with 1 mg/ml IgG (p = 0.003) and 10 mg/ml IgG (p = 0.002), respectively. In vivo, CPS-induced IgG reduced liver-stage infection and/or development after a mosquito infection in the human liver-chimeric mouse model by 91.05% when comparing 11 mice receiving post-immunization IgG to 11 mice receiving pre-immunization IgG (p = 0.0008). CONCLUSIONS: It is demonstrated for the first time that CPS-immunization induces functional antibodies against P. falciparum sporozoites, which are able to reduce parasite-host cell interaction by inhibiting parasite traversal and liver-stage infection. These data highlight the functional contribution of antibody responses to pre-erythrocytic immunity after whole-parasite immunization against P. falciparum malaria

Measurement by membrane feeding of reduction in plasmodium falciparum transmission induced by endemic sera.

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Studying the effect of chloroquine on sporozoite-induced protection and immune responses in Plasmodium berghei malaria

BACKGROUND: Sporozoite immunization of animals and humans under a chemo-prophylactic cover of chloroquine (CPS-CQ) efficiently induces sterile protection against malaria. In humans, CPS-CQ is strikingly more efficient than immunization with radiation attenuated sporozoites (RAS), raising the hypothesis that this might be partially due to CQ. Chloroquine, an established anti-malarial drug, is also well known for its immune modulating properties including improvement of cross-presentation. The aim of this study was to investigate whether co-administration of CQ during sporozoite immunization improves cellular responses and protective efficacy in Plasmodium berghei models. METHODS: A number of experiments in selected complimentary P. berghei murine models in Balb/cByJ and C57BL/6j mice was performed. First, the effect of CQ administration on the induction of protection and immune responses by RAS immunization was studied. Next, the effect of CQ on the induction of circumsporozoite (CS) protein-specific CD8(+) T cells by immunization with P. berghei parasites expressing a mutant CS protein was investigated. Finally, a direct comparison of CPS-CQ to CPS with mefloquine (MQ), an anti-malarial with little known immune modulating effects, was performed. RESULTS: When CQ was co-administered during immunization with graded numbers of RAS, this did not lead to an increase in frequencies of total memory CD8(+) T cells or CS protein-specific CD8(+) T cells. Also parasite-specific cytokine production and protection remained unaltered. Replacement of CQ by MQ for CPS immunization resulted in significantly reduced percentages of IFNgamma producing memory T cells in the liver (p = 0.01), but similar protection. CONCLUSIONS: This study does not provide evidence for a direct beneficial effect of CQ on the induction of sporozoite-induced immune responses and protection in P. berghei malaria models. Alternatively, the higher efficiency of CPS compared to RAS might be explained by an indirect effect of CQ through limiting blood-stage exposure after immunization or to increased antigen exposure and, therefore, improved breadth of the immune response