854 research outputs found

    Test-takers Perceptions of Test Fairness: A Washback Study on Test Information Given Prior to a High-stakes Writing Test

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    The development of conceptual frameworks for fairness in language testing has significantly expanded the scope of discussions on fairness. Empirical research motivated by these theories, however, has been minimal. There is no research, for example, that thoroughly examines the perceptions of test takers concerning fairness as outlined in the frameworks. Taking the context of the admissions officer system of universities in Korea, this paper looks at how the information released by universities before their exams affect students perceptions of test fairness. Furthermore, the paper attempts to examine the washback of such perceptions as test-takers prepare for the test. Two Korean universities that conducted written tasks for its early admissions processes were selected. Participants were six actual test-takers, who were extensively surveyed and interviewed. The results show that students placed much more faith in the assessment when the information regarding the test construct was relayed in a clear and consistent manner. Such results suggest that test developers need to pay acute attention to the information they provide to test-takers prior to the test, and that test-takers should be aware of the rights that they have regarding the disclosure of test information

    Smartphone dependence classification using tensor factorization

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    Excessive smartphone use causes personal and social problems. To address this issue, we sought to derive usage patterns that were directly correlated with smartphone dependence based on usage data. This study attempted to classify smartphone dependence using a data-driven prediction algorithm. We developed a mobile application to collect smartphone usage data. A total of 41,683 logs of 48 smartphone users were collected from March 8, 2015, to January 8, 2016. The participants were classified into the control group (SUC) or the addiction group (SUD) using the Korean Smartphone Addiction Proneness Scale for Adults (S-Scale) and a face-to-face offline interview by a psychiatrist and a clinical psychologist (SUC = 23 and SUD = 25). We derived usage patterns using tensor factorization and found the following six optimal usage patterns: 1) social networking services (SNS) during daytime, 2) web surfing, 3) SNS at night, 4) mobile shopping, 5) entertainment, and 6) gaming at night. The membership vectors of the six patterns obtained a significantly better prediction performance than the raw data. For all patterns, the usage times of the SUD were much longer than those of the SUC. From our findings, we concluded that usage patterns and membership vectors were effective tools to assess and predict smartphone dependence and could provide an intervention guideline to predict and treat smartphone dependence based on usage data.112Ysciescopu

    An autoregulatory loop controlling orphan nuclear receptor DAX-1 gene expression by orphan nuclear receptor ERRĪ³

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    The estrogen receptor-related receptor gamma (ERRĪ³/ERR3/NR3B3) is a member of the nuclear receptor superfamily that activates transcription in the absence of ligand. However, the detailed mechanism of gene regulation by ERRĪ³ is not fully understood. In this study we have found that the orphan nuclear receptor ERRĪ³ activates the DAX-1 promoter, which, in turn, represses transactivation by ERRĪ³. Serial deletions of mouse DAX-1 (mDAX-1) gene promoter have revealed that the region responding to ERRĪ³ is located between āˆ’129 and āˆ’121 bp and āˆ’334 and āˆ’326 bp. Gel shift assays and chromatin immunoprecipitation (ChIP) assays demonstrated that ERRĪ³ binds directly to the mDAX-1 promoter. Site-directed mutagenesis results demonstrated that ERRE1 (āˆ’129 to āˆ’121 bp) is more important than ERRE2 (āˆ’334 to āˆ’326 bp) which is not conserved in the human DAX-1 promoter. In addition, adenovirus-mediated overexpression of ERRĪ³ induced DAX-1 gene expression in MCF-7 breast cancer cells that co-expressed ERRĪ³ and DAX-1. Moreover, yeast two-hybrid and glutathione S-transferase (GST)-pull down assays demonstrated that DAX-1 physically interacted with ERRĪ³ and inhibited ERRĪ³ transactivation, and that this interaction was dependent on the AF-2 domain of ERRĪ³. In addition, in vitro competition assays showed that DAX-1 inhibited PGC-1Ī± mediated ERRĪ³ transactivation, via competition between these two factors for the AF-2 binding domain. We thus propose a novel autoregulatory loop that controls DAX-1 gene expression by ERRĪ³

    Cell typeā€“dependent variation in paracrine potency determines therapeutic efficacy against neonatal hyperoxic lung injury

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    AbstractBackground aimsThe aim of this study was to determine the optimal cell type for transplantation to protect against neonatal hyperoxic lung injury. To this end, the inĀ vitro and inĀ vivo therapeutic efficacies and paracrine potencies of human umbilical cord bloodā€“derived mesenchymal stromal cells (HUMs), human adipose tissueā€“derived mesenchymal stromal cells (HAMs) and human umbilical cord blood mononuclear cells (HMNs) were compared.MethodsHyperoxic injury was induced inĀ vitro in A549 cells by challenge with H2O2. Alternatively, hyperoxic injury was induced in newborn Sprague-Dawley rats inĀ vivo by exposure to hyperoxia (90% oxygen) for 14 days. HUMs, HAMs or HMNs (5Ā Ć— 105 cells) were given intratracheally at postnatal dayĀ 5.ResultsHyperoxia-induced increases in inĀ vitro cell death and inĀ vivo impaired alveolarization were significantly attenuated in both the HUM and HAM groups but not in the HMN group. Hyperoxia impaired angiogenesis, increased the cell death and pulmonary macrophages and elevated inflammatory cytokine levels. These effects were significantly decreased in the HUM group but not in the HAM or HMN groups. The levels of human vascular endothelial growth factor and hepatocyte growth factor produced by donor cells were highest in HUM group, followed by HAM group and then HMN group.ConclusionsHUMs exhibited the best therapeutic efficacy and paracrine potency than HAMs or HMNs in protecting against neonatal hyperoxic lung injury. These cell type-dependent variations in therapeutic efficacy might be associated or mediated with the paracrine potency of the transplanted donor cells

    Overexpression of BrSAC1 encoding a phosphoinositide phosphatase isolated from Chinese cabbage (Brassica rapa L) improved tolerance to cold, dehydration, and salt stresses in transgenic tobacco

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    This study demonstrates the isolation and characterization of cDNA encoding a phosphoinositide phosphatase (PIP) from a stem cell cDNA library of Chinese cabbage (Brassica rapa) seedling. The full length gene (BrSAC1; GenBank accession no., GU434275) contained 1999 base pairs (bp), with an open reading frame of 1785 bp, encoding a polypeptide of 594 amino acids with a predicted molecular weight of 65 kDa, including a putative N-terminal signal peptide (the signal peptide counted within the 594 residues). Other regions found within the sequence include a conserved KXKXX COPI-binding motif and a consensus Cx5R (T/S) catalytic motif. BrSAC1 protein shares 92% identity with AtSac1B, and 86% identity with AtRHD4 at the amino acid level. Gene expression analyses revealed that BrsSAC1 was constitutively expressed at high levels in the pistil, stamen and flower bud, whereas it was expressed at low levels in the leaf and stem. In addition to injury, BrSAC1 expression was also induced in response to different types of stress condition, namely cold, desiccation, salt, submergence, abscisic acid and heavy metals. Overexpression of BrSAC1 in transgenic tobacco conferred tolerance to cold, dehydration, and salt stress at the seed germination/seedling stage as reflected by the percentage of germination/green seedlings, the fresh weight of seedlings and their development pattern. Our data suggest that BrSAC1 is an important stress response determinant in plants.Keywords: Abiotic stress, Brassica rapa, phosphoinositide phosphatase, transgenic plantAfrican Journal of Biotechnology Vol. 12(15), pp. 1782-179

    Enhancement of angiogenic and vasculogenic potential of endothelial progenitor cells by haptoglobin

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    AbstractEndothelial progenitor cells (EPCs) were transfected with the haptoglobin (Hp) gene to investigate the effect of Hp on cell function. Hp potentiated the gene expression of various pro-angiogenic factors in the EPCs. The Hp-modified EPCs also increased in vitro tube formation on Matrigel compared with control cells. In hindlimb ischaemia models, Hpā€“EPCs showed a greater ability for improving blood perfusion and recovery from ischaemic injury. These results indicate that Hp improves EPC function in neovasculogenesis, which suggests that ex vivo modification of EPCs with the Hp gene can be applied to the treatment of vascular damage
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