212 research outputs found

    Developing Web-Based Multimedia Tools to Evaluate Sociolinguistic Proficiency in Learners of Korean as a Second Language

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    This paper examines the first stage of development of Web-based tools to evaluate sociolinguistic proficiency in intermediate learners of Korean as a second language. Sociolinguistic proficiency in this paper is defined as the ability to use language appropriately to the social context. The tools were integrated in Moodle, a Web-based C MS(Course Management System). The tools consisted of four parts : 1) a pre-activity questionnaire on experience learning and using Korean from a sociolinguistic perspective; 2) a DCT activity consisting of five situations; 3) a writing activity consisting of two situations; and 4) a short post-activity questionnaire on the tools. For the DCT activity, were asked to write both parts of a two-or three-person dialogue and a photograph was given as visual stimulation. BBS comment boards in which participants to could post questions anonymously were included and responsed to Parts 2 and 3 allowed for feedback. These features that can be used for mentoring. The tools were tested in a small-scale pilot study and testing will continue on an ongoing basis before the materials will be used for sociolinguistic proficiency evaluation and research

    IL-22 regulates lymphoid chemokine production and assembly of tertiary lymphoid organs

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    The series of events leading to tertiary lymphoid organ (TLO) formation in mucosal organs following tissue damage remain unclear. Using a virus-induced model of autoantibody formation in the salivary glands of adult mice, we demonstrate that IL-22 provides a mechanistic link between mucosal infection, B-cell recruitment, and humoral autoimmunity. IL-22 receptor engagement is necessary and sufficient to promote differential expression of chemokine (C-X-C motif) ligand 12 and chemokine (C-X-C motif) ligand 13 in epithelial and fibroblastic stromal cells that, in turn, is pivotal for B-cell recruitment and organization of the TLOs. Accordingly, genetic and therapeutic blockade of IL-22 impairs and reverses TLO formation and autoantibody production. Our work highlights a critical role for IL-22 in TLO-induced pathology and provides a rationale for the use of IL-22ā€“blocking agents in B-cellā€“mediated autoimmune conditions

    Interleukin-22 Protects Intestinal Stem Cells from Immune-Mediated Tissue Damage and Regulates Sensitivity to Graft versus Host Disease

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    SummaryLittle is known about the maintenance of intestinal stem cells (ISCs) and progenitors during immune-mediated tissue damage or about the susceptibility of transplant recipients to tissue damage mediated by the donor immune system during graft versus host disease (GVHD). We demonstrate here that deficiency of recipient-derived IL-22 increased acute GVHD tissue damage and mortality, that ISCs were eliminated during GVHD, and that ISCs as well as their downstream progenitors expressed the IL-22 receptor. Intestinal IL-22 was produced after bone marrow transplant by IL-23-responsive innate lymphoid cells (ILCs) from the transplant recipients, and intestinal IL-22 increased in response to pretransplant conditioning. However, ILC frequency and IL-22 amounts were decreased by GVHD. Recipient IL-22 deficiency led to increased crypt apoptosis, depletion of ISCs, and loss of epithelial integrity. Our findings reveal IL-22 as a critical regulator of tissue sensitivity to GVHD and a protective factor for ISCs during inflammatory intestinal damage

    Chronic mucocutaneous candidiasis in APECED or thymoma patients correlates with autoimmunity to Th17-associated cytokines

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    Chronic mucocutaneous candidiasis (CMC) is frequently associated with T cell immunodeficiencies. Specifically, the proinflammatory IL-17Aā€“producing Th17 subset is implicated in protection against fungi at epithelial surfaces. In autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED, or autoimmune polyendocrine syndrome 1), CMC is often the first sign, but the underlying immunodeficiency is a long-standing puzzle. In contrast, the subsequent endocrine features are clearly autoimmune, resulting from defects in thymic self-tolerance induction caused by mutations in the autoimmune regulator (AIRE). We report severely reduced IL-17F and IL-22 responses to both Candida albicans antigens and polyclonal stimulation in APECED patients with CMC. Surprisingly, these reductions are strongly associated with neutralizing autoantibodies to IL-17F and IL-22, whereas responses were normal and autoantibodies infrequent in APECED patients without CMC. Our multicenter survey revealed neutralizing autoantibodies against IL-17A (41%), IL-17F (75%), and/ or IL-22 (91%) in >150 APECED patients, especially those with CMC. We independently found autoantibodies against these Th17-produced cytokines in rare thymoma patients with CMC. The autoantibodies preceded the CMC in all informative cases. We conclude that IL-22 and IL-17F are key natural defenders against CMC and that the immunodeficiency underlying CMC in both patient groups has an autoimmune basis

    Population Genomics of Intron Splicing in 38 Saccharomyces cerevisiae Genome Sequences

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    Introns are a ubiquitous feature of eukaryotic genomes, and the dynamics of intron evolution between species has been extensively studied. However, comparatively few analyses have focused on the evolutionary forces shaping patterns of intron variation within species. To better understand the population genetic characteristics of introns, we performed an extensive population genetics analysis on key intron splice sequences obtained from 38 strains of Saccharomyces cerevisiae. As expected, we found that purifying selection is the dominant force governing intron splice sequence evolution in yeast, formally confirming that intron-containing alleles are a mutational liability. In addition, through extensive coalescent simulations, we obtain quantitative estimates of the strength of purifying selection (2Nes ā‰ˆ 19) and use diffusion approximations to provide insights into the evolutionary dynamics and sojourn times of newly arising splice sequence mutations in natural yeast populations. In contrast to previous functional studies, evolutionary analyses comparing the prevalence of introns in essential and nonessential genes suggest that introns in nonribosomal protein genes are functionally important and tend to be actively maintained in natural populations of S. cerevisiae. Finally, we demonstrate that heritable variation in splicing efficiency is common in intron-containing genes with splice sequence polymorphisms. More generally, our study highlights the advantages of population genomics analyses for exploring the forces that have generated extant patterns of genome variation and for illuminating basic biological processes

    The Extracellular Matrix and Blood Vessel Formation: Not Just a Scaffold

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    The extracellular matrix plays a number of important roles, among them providing structural support and information to cellular structures such as blood vessels imbedded within it. As more complex organisms have evolved, the matrix ability to direct signalling towards the vasculature and remodel in response to signalling from the vasculature has assumed progressively greater importance. This review will focus on the molecules of the extracellular matrix, specifically relating to vessel formation and their ability to signal to the surrounding cells to initiate or terminate processes involved in blood vessel formation
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