1,736 research outputs found

    In the absence of CD154, administration of interleukin-12 restores Th1 responses but not protective immunity to Schistosoma mansoni

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    The cytokine interplay during the development of protective immunity to the radiation-attenuated (RA) schistosome vaccine has been extensively characterized over recent years, yet the role of costimulatory molecules in the development of cell-mediated immunity is much less well understood. Here we demonstrate the importance of CD40/CD154 in vaccine-induced immunity, as CD154(-/-) mice exposed to RA schistosomes develop no protection to challenge infection. We showed that vaccinated CD154(-/-) mice have defective Th1-associated immune responses in the skin-draining lymph nodes and the lungs, with reduced or absent levels of interleukin-12p40 (IL-12p40), gamma interferon, and nitric oxide, but elevated levels of lung IL-4 and IL-5. The expression of major histocompatibility complex II (MHC-II) on antigen-presenting cells recovered from the lungs of vaccinated CD154(-/-) mice was also severely compromised. The administration of anti-CD40 monoclonal antibody (MAb) to CD154(-/-) mice did not reconstitute sustained Th1 responses in the lymph nodes or the lungs, nor did the MAb restore anti-parasite immunoglobulin G production or protective immunity. On the other hand, the administration of recombinant IL-12 (rIL-12) to CD154(-/-) mice shortly after vaccination caused elevated and sustained levels of Th1-associated cytokines, rescued MHC-II expression by lung CD11c(+) cells, and restored the appearance of inflammatory effector foci in the lungs. However, the treatment of CD154(-/-) mice with rIL-12 did not restore protection. We conclude that protective immunity to the RA schistosome vaccine is CD154 dependent but is independent of IL-12-orchestrated cellular immune mechanisms in the lungs

    Assessment of calibration accuracy of Pacific University\u27s Goldmann tonometers

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    In the therapeutic management of glaucoma, the clinician must determine a target intraocular pressure (IOP). Goldmann applanation tonometry is the standard of care for measuring IOP. This study investigates the calibration accuracy of the Goldmann tonometers in Pacific University\u27s primary care and ocular disease clinics to see if variations when using different Goldmann tonometers on successive visits could significantly affect the outcome of IOP measurement. Our results showed that the Goldamnn tonometers at Pacific University\u27s optometry clinics are sufficiently calibrated and will have an insignifcant effect on the determination of achievement of target IOP when therapeutically managing glaucoma

    Lupinosis : a disease still with us

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    Current research on lupinosis continues to reveal what a complex problem it is, but the improved understanding should help to reduce losses

    Analysis of Dialogical Argumentation via Finite State Machines

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    Dialogical argumentation is an important cognitive activity by which agents exchange arguments and counterarguments as part of some process such as discussion, debate, persuasion and negotiation. Whilst numerous formal systems have been proposed, there is a lack of frameworks for implementing and evaluating these proposals. First-order executable logic has been proposed as a general framework for specifying and analysing dialogical argumentation. In this paper, we investigate how we can implement systems for dialogical argumentation using propositional executable logic. Our approach is to present and evaluate an algorithm that generates a finite state machine that reflects a propositional executable logic specification for a dialogical argumentation together with an initial state. We also consider how the finite state machines can be analysed, with the minimax strategy being used as an illustration of the kinds of empirical analysis that can be undertaken.Comment: 10 page

    Continuous cereal cropping with alternative tillage systems in Western Australia

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    In 1977, a ten year series of continuous cropping trials was commenced to compare the effect of four farm tillage systems. This bulletin reports the grain yield results for the first six years of these trials

    Relating imperatives to action

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    The aim of this chapter is to provide an analysis of the use of logically complex imperatives, in particular, imperatives of the form Do A1 or A2 and Do A, if B. We argue for an analysis of imperatives in terms of classical logic which takes into account the influence of background information on imperatives. We show that by doing so one can avoid some counter-intuitive results which have been associated with analyses of imperatives in terms of classical logic. In particular, I address Hamblin's observations concerning rule-like imperatives and Ross' Paradox. The analysis is carried out within an agent-based logical framework. This analysis explicates what it means for an agent to have a successful policy for action with respect to satisfying his or her commitments, where some of these commitments have been introduced as a result of imperative language use

    Phomopsis-resistanct lupins : breakthrough towards the control of lupinosis

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    Attemots to control lupinosis in sheep have been thwarted by the unpredictable occurence of the disease in the field. The complex interaction of the toxin-producing fungus (Phomopsis leptostromiformis) with its host (the lupin plant), together with variable weather and paddock grazing conditions, have made it difficult to predict when stock are in danger of contracting the disease. The risk of lupinosis discourages many farmers from growing lupins, despite the many potential benefits of including them in crop rotations. A team of Department of Agriculture plant breeders, plant pathologists, and animal scientists set out in the mid 1970s to find resistance to the Phomopsis fungus in lupins. Their goal was to find resistance that prevented the fungus from colonising and producing toxin in lupin stubbles. A decade of work has culminated in the development of lupin breeding lines with low visible symptoms of Phomopsis in the stubble and, most importantly, low stubble toxixity. This article summarises the long-term research programme

    Water use of alternative wheatbelt crop species

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    84M5, 84M6, 84M7. Location: Merredin Research Station Merredin, Western Australia. Three experiments were conducted to measure the productivity and water use of alternative wheatbelt crop species on contrasting soil types in a dry mediterranean environment. Crop species investigated were wheat, barley, cereal rye, narrow leafed lupin and field pea. These were grown on three contrasting soil types, a red-brown earth, a sandy loam over clay and a deep loamy sand; all soils occurring within close proximity to each other. Detailed measurements were made of meteorological conditions, dry matter production, leaf area, root growth, soil water profiles, light interception and plant water status. This report gives the background and significance of the study, the methods employed and results obtained
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