1,245 research outputs found

    Characterization of the T cell receptor repertoire causing collagen arthritis in mice

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    Collagen type II-induced arthritis (CIA) is generated in susceptible rodent strains by intradermal injections of homologous or heterologous native type II collagen in complete Freund's adjuvant. Symptoms of CIA are analogous to those of the human autoimmune disease, rheumatoid arthritis. CIA is a model system for T cell-mediated autoimmune disease. To study the T cell receptor (TCR) repertoire of bovine type II-specific T cells that may be involved in the pathogenesis of CIA in DBA/1Lac.J (H-2q) mice, 13 clonally distinct T cell hybridomas specific for bovine type II collagen have been established and the alpha and beta chains of their TCRs have been analyzed. These T cell hybridomas recognize epitopes that are shared by type II collagens from distinct species and not by type I collagens, and exhibit a highly restricted TCR-alpha/beta repertoire. The alpha chains of the TCRs employ three V alpha gene subfamilies (V alpha 11, V alpha 8, and V alpha 22) and four J alpha gene segments (J alpha 42, J alpha 24, J alpha 37, and J alpha 32). The V alpha 22 is a newly identified subfamily consisting of approximately four to six members, and exhibits a high degree of polymorphism among four mouse strains of distinct V alpha haplotypes. In addition, the beta chains of the TCRs employ three V beta gene subfamilies (V beta 8, V beta 1, and V beta 6), however the V beta 8.2 gene segment is preferentially utilized (58.3%). In contrast, the J beta gene segment usage is more heterogeneous. On the basis of the highly limited TCR-alpha/beta repertoire of the TCRs of the panel of bovine type II-specific T cell hybrid clones, a significant reduction (60%) of the incidence of arthritis in DBA/1Lac.J mice is accomplished by the use of anti-V beta 8.2 antibody therapy

    IMPROVING IRRIGATION WATER ALLOCATION EFFICIENCY USING ALTERNATIVE POLICY OPTIONS IN EGYPT

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    This study provides an empirical perspective on alternative irrigation policies for allocating limited water to agricultural production in Egypt. Positive mathematical programming is used for model calibration. Three policy options for Egypt are tested: water pricing, water complementary input factor taxes, and output taxes. The results of the research show that: 1) water pricing needs to be much higher than the recovery cost in order to be effective in limiting irrigation water use; 2) at a higher tax rate, fertilizer and energy taxes are effective in reducing the irrigation water demand while maintaining adequate welfare levels; 3) a pesticide tax is less effective than fertilizer or energy taxes; and 4) an output tax on sugar cane and rice would decrease irrigation water demand substantially while allocating land to other crops which are less water intensive and have higher market values.Resource /Energy Economics and Policy,

    The conversation: developing confidence to provide end of life care in Salford nursing homes

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    The study was funded by the Burdett Trust for Nursing and partly by Salford Primary Care Trust. A realistic evaluation design was used to collect data using a range of approaches, from before and after surveys of confidence in delivering end of life care, to participant observation and interviews. A total of 43 people were interviewed involving both staff, residents and relatives. Key Messages a) Significant resources are needed to engage staff, residents and relatives/carers with the idea of advance care planning b) Care home staff are optimistic about involving residents and relatives in planning care at the end of life and some relatives become very involved in care c) Clearly registered nurses and other care home workers such as care assistants have different roles, but the overlap between these and the appropriate boundaries would benefit from further work d) Talking to residents and relatives about their feelings and wishes for care at the end of life remains especially difficult, but education and training in key skills and knowledge can engender both ability and motivation e) Care homes need strong and well-informed leadership in order to implement the Gold Standards Framework f) Placing a relative in a care home involves strain and an ability to compromise ‘there’s no perfect place’ g) Advance care planning can reduce the distress and the number of inappropriate hospital admissions, but is challenging in the face of staff rotation and out of hours medical staff being unpredictable h) The principles of the Gold Standards Framework are widely seen as sensible, but clinical challenges include diagnosing and predicting dying trajectories, especially in heart failure, chronic pulmonary disease and dementia i) A particular concern of staff is how to approach nutrition and hydration as frailty and death approach j) Communicating about diagnosis and especially prognosis with residents who lack capacity is an increasing problem k) Natural justice suggests that resources should be allocated to the general standardisation of a good quality of care at the end of life in ALL care homes whatever their Care Quality Commission ratin

    Strategic Policy Options to Improve Irrigation Water Allocation Efficiency: Analysis on Egypt and Morocco

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    For a number of reasons government the world over have been unwilling to use water pricing to achieve water use efficiency. This research addresses questions of what policy alternatives to water pricing might improve irrigation water allocation efficiency. An empirical framework is provided to compare irrigation policies for allocating scarce water to agricultural production in Egypt and Morocco. Partial equilibrium agricultural sector models specific to Egypt and Morocco were employed for policy tests. Positive Mathematical Programming (PMP) was used to calibrate the models. Water pricing policy, water complementary input factor tax policy, and output tax policy are tested. Results suggest that effective policy depends on the social, economic, and environmental contexts of specific regions. The results for both countries demonstrate that some of the alternative irrigation policies can work towards directing cropping decisions to less water intensive crops and also generating revenues for governments in situations where governments choose not to price water.Resource /Energy Economics and Policy,

    Microstructural analysis of surface and interface zones in concrete

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    Several of OPC paste and concrete specimens, with different mix proportions, were cast against CPF and impermeable formwork (IF) and the profiles of pore structure, microhardness and scratch hardness of the cover zone were established. The chloride ingress and the depth of carbonation of the surface zone of concrete cast against CPF and IF were investigated. The main mechanisms controlling the ECR processes and the factors affecting such treatment were critically reviewed. Subsequently, as a means of restoring passivation of steel embedded in carbonated concrete, such HCP specimens were subjected to ECR. The influence of ECR on the chemistry of the pore solution and the microstructure of the surface and the steel/cement past interface zones were also studied. The main findings of this investigation were as follows: (a) The thickness of the microstructure gradient of cover concrete is significantly decreased with increasing period of water curing but is relatively unaffected by curing temperature, w/e ratio and the use of cement replacement materials. (b) The scratch hardness technique was shown to be potentially useful for characterising the microstructure and microhardness gradients of the surface zone. (c) A relationship between the microstructure gradient and mass transport properties of the surface zone was established. (d) The use of CPF resulted in a significant reduction in porosity of both the cement paste matrix and the aggregate/cement paste transition zone, and a marked improvement in the resistance of the surface zone to carbonation and the ingress of chloride ions. (e) The ECR treatment resulted in a marked densification of the pore structure and in changes to the pore solution chemistry and the cement phases of near-surface and steel/cement paste transition zones. This effect was more pronounced with current density, period of treatment and particularly with the use of sodium phosphate as an electrolyte

    A rapid method for computing the inverse of the gametic covariance matrix between relatives for a marked Quantitative Trait Locus

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    The inverse of the gametic covariance matrix between relatives, G-1, for a marked quantitative trait locus (QTL) is required in best linear unbiased prediction (BLUP) of breeding values if marker data are available on a QTL. A rapid method for computing the inverse of a gametic relationship matrix for a marked QTL without building G itself is presented. The algorithm is particularly useful due to the approach taken in computing inbreeding coefficients by having to compute only few elements of G. Numerical techniques for determining, storing, and computing the required elements of G and the nonzero elements of the inverse are discussed. We show that the subset of G required for computing the inbreeding coefficients and hence the inverse is a tiny proportion of the whole matrix and can be easily stored in computer memory using sparse matrix storage techniques. We also introduce an algorithm to determine the maximum set of nonzero elements that can be found in G-1 and a strategy to efficiently store and access them. Finally, we demonstrate that the inverse can be efficiently built using the present techniques for very large and inbred populations
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