28 research outputs found

    ASG Student Social and Emotional Health Report

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    This report presents the results of sophisticated Rasch measurement analysis and multi-level modelling to validate and support the use of the ACER Social and Emotional Wellbeing (SEWB) student and teacher surveys for reporting on the social and emotional well-being of students from the early years of schooling through to senior secondary school levels. It describes the social and emotional well-being of over 10,000 students attending 81 schools across Australia. Among the more important findings of this research are the characteristics of students with low levels of social and emotional well-being compared with students with higher levels of social and emotional well-being

    The structure of the KlcA and ArdB proteins reveals a novel fold and antirestriction activity against Type I DNA restriction systems in vivo but not in vitro

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    Plasmids, conjugative transposons and phage frequently encode anti-restriction proteins to enhance their chances of entering a new bacterial host that is highly likely to contain a Type I DNA restriction and modification (RM) system. The RM system usually destroys the invading DNA. Some of the anti-restriction proteins are DNA mimics and bind to the RM enzyme to prevent it binding to DNA. In this article, we characterize ArdB anti-restriction proteins and their close homologues, the KlcA proteins from a range of mobile genetic elements; including an ArdB encoded on a pathogenicity island from uropathogenic Escherichia coli and a KlcA from an IncP-1b plasmid, pBP136 isolated from Bordetella pertussis. We show that all the ArdB and KlcA act as anti-restriction proteins and inhibit the four main families of Type I RM systems in vivo, but fail to block the restriction endonuclease activity of the archetypal Type I RM enzyme, EcoKI, in vitro indicating that the action of ArdB is indirect and very different from that of the DNA mimics. We also present the structure determined by NMR spectroscopy of the pBP136 KlcA protein. The structure shows a novel protein fold and it is clearly not a DNA structural mimic

    STAT3 in epithelial cells regulates inflammation and tumor progression to malignant state in colon

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    AbstractChronic inflammation is an important risk factor for the development of colorectal cancer; however, the mechanism of tumorigenesis especially tumor progression to malignancy in the inflamed colon is still unclear. Our study shows that epithelial signal transducer and activator of transcription 3 (STAT3), persistently activated in inflamed colon, is not required for inflammation-induced epithelial overproliferation and the development of early-stage tumors; however, it is essential for tumor progression to advanced malignancy. We found that one of the mechanisms that epithelial STAT3 regulates in tumor progression might be to modify leukocytic infiltration in the large intestine. Activation of epithelial STAT3 promotes the infiltration of the CD8+ lymphocyte population but inhibits the recruitment of regulatory T (Treg) lymphocytes. The loss of Stat3 in epithelial cells promoted the expression of cytokines/chemokines including CCL19, CCL28, and RANTES, which are known to be able to recruit Treg lymphocytes. Linked to these changes was the pathway mediated by sphingosine 1-phosphate receptor 1 and sphingosine 1-phosphate kinases, which is activated in colonic epithelial cells in inflamed colon with functional STAT3 but not in epithelial cells deleted of STAT3. Our data suggest that epithelial STAT3 plays a critical role in inflammation-induced tumor progression through regulation of leukocytic recruitment especially the infiltration of Treg cells in the large intestine

    Constructing Scales for Reporting Growth in Numeracy : The ACER Longitudinal Literacy and Numeracy Study

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    The ACER Longitudinal Literacy and Numeracy Study is set within the conceptual framework of developmental assessment. This paper describes work done on the development of a numeracy scale, and demonstrates how the progressive achievement of the LLANS cohort of students can be reported on that scale and subscales

    Growth in Literacy and Numeracy in the First Three Years of School.

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    This report describes the findings from the first three years of the ACER longitudinal Literacy and Numeracy Study (LLANS). The longitudinal study was established in 1999 in a context in which there was significant national interest in improving achievement in literacy and numeracy for all Australian children, and a particular interest in the development of foundational skills in the early years of school. A nation wide sample of 100 schools was selected in proportion to the population of each state and territory and ten students were randomly selected from each of these schools. This provided a cohort for LLANS of 1000 children who commenced school in 1999. The longitudinal study continued beyond the first three years of school until 2005 when the students in the sample were in year 6

    A VEGF/JAK2/STAT5 axis may partially mediate endothelial cell tolerance to hypoxia

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    Perturbation of oxygen flow occurs in disease states such as diabetic retinopathy and cancer. To maintain oxygen homoeostasis, the mammalian microvascular endothelium undergoes a dramatic reorganization to assist in bringing oxygen and nutrients to oxygen-starved tissues. This process is termed angiogenesis and is common in certain cancers with hypoxic foci and in areas of focal ischaemia in the diabetic retina. In the present study, we report on the activation of the JAK2/STAT5 pathway (where JAK stands for Janus kinase and STAT stands for signal transduction and activator of transcription) by low oxygen in microvascular endothelial cells. This activation appears to occur downstream of VEGF (vascular endothelial growth factor), a well-known proangiogenic factor, and is related to repression of proapoptotic FAS(CD95)/FASL(CD95L). These results indicate that the JAK/STAT pathway may play a pivotal role during tumour-associated or retinal angiogenesis in which endothelial cell survival during tissue hypoxia is critical for maintaining either the growth of neoplasms or the inappropriate retinal neovascularization common in diabetic retinopathy

    Urocortin prevents mitochondrial permeability transition in response to reperfusion injury indirectly by reducing oxidative stress

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    Urocortin (UCN) protects hearts against ischemia and reperfusion injury whether given before ischemia or at reperfusion. Here we investigate the roles of PKC, reactive oxygen species, and the mitochondrial permeability transition pore (MPTP) in mediating these effects. In Langendorff-perfused rat hearts, acute UCN treatment improved hemodynamic recovery during reperfusion after 30 min of global ischemia; this was accompanied by less necrosis (lactate dehydrogenase release) and MPTP opening (mitochondrial entrapment of 2-[(3)H]deoxyglucose). UCN pretreatment protected mitochondria against calcium-induced MPTP opening, but only if the mitochondria had been isolated from hearts after reperfusion. These mitochondria also exhibited less protein carbonylation, suggesting that UCN decreases levels of oxidative stress. In isolated adult and neonatal rat cardiac myocytes, both acute (60 min) and chronic (16 h) treatment with UCN reduced cell death following simulated ischemia and re-oxygenation. This was accompanied by less MPTP opening as measured using tetramethylrhodamine methyl ester. The level of oxidative stress during reperfusion was reduced in cells that had been pretreated with UCN, suggesting that this is the mechanism by which UCN desensitizes the MPTP to reperfusion injury. Despite the fact that we could find no evidence that either PKC-epsilon or PKC-alpha translocate to the mitochondria following acute UCN treatment, inhibition of PKC with chelerythrine eliminated the effect of UCN on oxidative stress. Our data suggest that acute UCN treatment protects the heart by inhibiting MPTP opening. However, the mechanism appears to be indirect, involving a PKC-mediated reduction in oxidative stress

    Novel IL-21 signaling pathway up-regulates c-Myc and induces apoptosis of diffuse large B-cell lymphomas

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    Interleukin-21 (IL-21), a member of the IL-2 cytokine family, has diverse regulatory effects on natural killer (NK), T, and B cells. In contrast to other cytokines that are usually immunostimulatory, IL-21 can induce apoptosis of murine B cells at specific activation-differentiation stages. This effect may be used for treatment of B-cell malignancies. Herein we report that diffuse large B-cell lymphoma (DLBCL) cell lines exhibit widespread expression of the IL-21 receptor (IL-21R) and that IL-21 stimulation leads to cell-cycle arrest and caspase-dependent apoptosis. IL-21 also induces apoptosis in de novo DLBCL primary tumors but does not affect viability of human healthy B cells. Furthermore, IL-21 promotes tumor regression and prolongs survival of mice harboring xenograft DLBCL tumors. The antilymphoma effects of this cytokine are dependent on a mechanism involving IL-21–activated signal transducer and activator of transcription 3 (STAT3) up-regulating expression of c-Myc. This up-regulation promotes a decrease in expression of antiapoptotic Bcl-2 and Bcl-XL proteins triggering cell death. Our results represent one of the first examples in which the STAT3–c-Myc signaling pathway, which can promote survival and oncogenesis, can induce apoptosis in neoplastic cells. Moreover, based on IL-21's potency in vitro and in animal models, our findings indicate that this cytokine should be examined in clinical studies of DLBCL
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