371 research outputs found

    Coeliac disease pathogenesis: The uncertainties of a well-known immune mediated disorder

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    Coeliac disease is a common small bowel enteropathy arising in genetically predisposed individuals and caused by ingestion of gluten in the diet. Great advances have been made in understanding the role of the adaptive immune system in response to gluten peptides. Despite detailed knowledge of these adaptive immune mechanisms, the complete series of pathogenic events responsible for development of the tissue lesion remains less certain. This review contributes to the field by discussing additional mechanisms which may also contribute to pathogenesis. These include the production of cytokines such as interleukin-15 by intestinal epithelial cells and local antigen presenting cells as a pivotal event in the disease process. A subset of unconventional T cells called gamma/delta T cells are also persistently expanded in the coeliac disease (CD) small intestinal epithelium and recent analysis has shown that these cells contribute to pathogenic inflammation. Other unconventional T cell subsets may play a local immunoregulatory role and require further study. It has also been suggested that, in addition to activation of pathogenic T helper cells by gluten peptides, other peptides may directly interact with the intestinal mucosa, further contributing to the disease process. We also discuss how myofibroblasts, a major source of tissue transglutaminase and metalloproteases, may play a key role in intestinal tissue remodeling. Contribution of each of these factors to pathogenesis is discussed to enhance our view of this complex disorder and to contribute to a wider understanding of chronic immunemediated disease.Fil: Dunne, Margaret R.. St. James's Hospital. Trinity College Dublin. Trinity Translational Medicine Institute. Department of Surgery; IrlandaFil: Byrne, Greg. Technological University of Dublin. School of Biological & Health Sciences; IrlandaFil: Chirdo, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Feighery, Conleth. Trinity College Dublin; Irlanda. St. James’s Hospital; Irland

    Mott transition in the π\pi-flux SU(44) Hubbard model on a square lattice

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    We employ the projector quantum Monte Carlo simulations to study the ground-state properties of the square-lattice SU(4) Hubbard model with a π\pi flux per plaquette. In the weak coupling regime, its ground state is in the gapless Dirac semi-metal phase. With increasing repulsive interaction, we show that, a Mott transition occurs from the semimetal to the valence bond solid, accompanied by the Z4Z_4 discrete symmetry breaking. Our simulations demonstrate the existence of a second-order phase transition, which confirms the Ginzburg-Landau analysis. The phase transition point and the critical exponent η\eta are also estimated. To account for the effect of a π\pi flux on the ordering in the strong coupling regime, we analytically derive by the perturbation theory the ring-exchange term which describes the leading-order difference between the π\pi-flux and zero-flux SU(4) Hubbard models.Comment: 8 pages, 9 figure

    Long-term comparison between index selection and optimal independent culling in plant breeding programs with genomic prediction

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    In the context of genomic selection, we evaluated and compared breeding programs using either index selection or independent culling for recurrent selection of parents. We simulated a clonally propagated crop breeding program for 20 cycles using either independent culling or an economic index with two unfavourably correlated traits under selection. Cycle time from crossing to selection of parents was kept the same for both strategies. Both methods led to increasingly unfavourable genetic correlations between traits and, compared to independent culling, index selection led to larger changes in the genetic correlation between the two traits. When linkage disequilibrium was not considered, the two methods had similar losses of genetic diversity. Two independent culling approaches were evaluated, one using optimal culling levels and one using the same selection intensity for both traits. Optimal culling levels outperformed the same selection intensity even when traits had the same economic importance. Therefore, accurately estimating optimal culling levels is essential for maximizing gains when independent culling is performed. Once optimal culling levels are achieved, independent culling and index selection lead to comparable genetic gains

    Implications of an Ethic of Privacy for Human-Centred Systems Engineering

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    Privacy remains an intractable ethical issue for the information society. Given its complicity, there is a moral obligation to redress privacy issues in systems engineering practice itself. This paper investigates the role the concept of privacy plays in contemporary systems engineering practice. Ontologically a nominalist human concept, privacy is considered from an appropriate engineering perspective: human-centred design. Two human-centred design standards are selected as exemplars of best practice, and are analysed using an existing multi-dimensional privacy model. The findings indicate that the human-centred standards are currently inadequate in dealing with privacy issues. Some implications for future practice are subsequently highlighted

    Extracto acuoso de romero como inhibidor de la corrosión del acero SAE 1010 en NaCl 0,1 M

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    El tetroxicromato de zinc y el minio, pigmentos anticorrosivos tradicionalmente utilizados en pinturas, han sido ampliamente cuestionados por su toxicidad e impacto ambiental. En su reemplazo se han desarrollado tres generaciones de fosfatos, pero su excesivo uso va acompañado de la eutrofización en depósitos de agua dulce. Es por eso que surge la necesidad de utilizar como anticorrosivos compuestos o mezclas de compuestos de origen natural, entre los que se encuentran los extractos vegetales acuosos.Fil: Byrne, Christian Eduardo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Ramirez, Martin Gabriel. Universidad Tecnológica Nacional; ArgentinaFil: Di Santo, E.. Universidad Tecnológica Nacional; ArgentinaFil: Cristiano, Nicol. Universidad Tecnológica Nacional; ArgentinaFil: D'alessandro, Oriana. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaJornadas sobre Tecnología de Recubrimientos "Dr. Roberto Romagnoli"La PlataArgentinaCentro de Investigación y Desarrollo en Tecnología de PinturasUniversidad Nacional de La Plat

    The Food Allergy COPE Inventory: Adaptation and Psychometric Properties

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    Background Food allergy (FA) has been shown to have an adverse impact on food allergy quality of life (FAQL). To more fully understand this impact, correlates and predictors of FAQL must be reliably measured. Coping is one such factor. In the present study (n = 200), we sought to adapt the widely used COPE Inventory and its 15 distinct strategies to food allergy, named FA COPE Inventory. More specifically, we propose a long (60-item) and short (30-item) version of the measure. Methods To examine the robustness of the newly adapted FA COPE Inventory, we tested whether the 15-factor structure of the adapted version would present good psychometrical properties, using gold standard psychometric techniques. We used Confirmatory Factor Analysis to assess model fit, McDonald’s omega, and inter-item correlations to assess reliability, and Pearson’s correlation to assess convergent validity with a generic coping measure and satisfaction with FA life. Results Our results showed a good model fit (e.g., CFI and TLI ≥ .94) for the 15-factor structure of the measure's long and short version. These factors also presented reliability levels aligned with the coping literature. Finally, the majority of the FA-COPE Inventory factors (e.g., acceptance) were significantly associated with the generic coping measure and satisfaction with FA life. Conclusion Both the long and short adapted FA COPE Inventory showed a good fit to food allergy issues. These measures can help facilitate the identification of the most commonly used strategies to deal with FA. Their use can lead to a more in-depth understanding of the impact of the coping strategies and how they can help improve the quality of life of those impacted by the disease
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