189 research outputs found

    Doctoral Students' Perceptions of Self-Determination for Students with Disabilities

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    The purpose of this study is to investigate special education doctoral students' perceptions of self-determination for students with disabilities. This study is designed to examine what doctoral students who are preparing for the future role as faculty in special education know about self-determination and their views related its importance in their own studies and in future teaching. Specifically, this study identifies doctoral students' knowledge of and general attitude toward self-determination. For this, an extensive literature review has been conducted in the area of self-determination for students with disabilities. This study uses the Doctoral Student's Perceptions of Self-Determination for Students with Disabilities survey (Kim, in press). The survey was developed to gather information about doctoral students' perceptions of self-determination for students with disabilities. Ninety-nine doctoral students majoring in special education completed the survey. The results of this study suggested that the high number of special education doctoral students as pre-faculty members in special education departments indicated they understood the definition and components of self-determination. However, they need to have more sufficient knowledge about self-determination such as assessment, curricula, issues and trends. In addition, the results indicated that a majority of the doctoral students believed that self-determination is one of the most important skill sets acquired by students with disabilities, and they were willing to integrate self-determination knowledge and skills into their future teaching. Finally, limitations of this study and implications for further research are discussed

    Critical organizational success factors for public private partnership projects – a comparison of solicited and unsolicited proposals

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    Public Private Partnership (PPP) projects are typically initiated through solicited or unsolicited proposals. The difference between the processes according to the proposal mode often leads to different levels of involvement and responsibilities for the public and private sectors. However, no robust research exists to capture the differences, depending on the proposal mode, in the roles and involvement of project participants and the impact of those differences on project success. This study intends to explore the critical organizational success factors contributing to the success of PPP projects according to the proposal mode and to provide practical recommendations for project success from organizational perspectives. To assess the factors, 141 questionnaire surveys were conducted with participants in 32 PPP projects. The major findings indicated that “Project Implementation Capability” had the most critical influence on solicited projects, whereas “Risk Sharing and Mitigation Strategies” was the most significant in unsolicited projects. In addition, “Interorganization Coordination” among project participants was essential to the success for both solicited and unsolicited projects. Government roles and involvement were also critical, although their contributions were relatively less important than other critical organizational success factors. Based on the findings, practical recommendations were provided for the success of solicited and unsolicited projects

    Role of S5b/PSMD5 in Proteasome Inhibition Caused by TNF-α/NFκB in Higher Eukaryotes

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    SummaryThe ubiquitin-proteasome system is essential for maintaining protein homeostasis. However, proteasome dysregulation in chronic diseases is poorly understood. Through genome-wide cell-based screening using 5,500 cDNAs, a signaling pathway leading to NFκB activation was selected as an inhibitor of 26S proteasome. TNF-α increased S5b (HGNC symbol PSMD5; hereafter S5b/PSMD5) expression via NFκB, and the surplus S5b/PSMD5 directly inhibited 26S proteasome assembly and activity. Downregulation of S5b/PSMD5 abolished TNF-α-induced proteasome inhibition. TNF-α enhanced the interaction of S5b/PSMD5 with S7/PSMC2 in nonproteasome complexes, and interference of this interaction rescued TNF-α-induced proteasome inhibition. Transgenic mice expressing S5b/PSMD5 exhibited a reduced life span and premature onset of aging-related phenotypes, including reduced proteasome activity in their tissues. Conversely, S5b/PSMD5 deficiency in Drosophila melanogaster ameliorated the tau rough eye phenotype, enhanced proteasome activity, and extended the life span of tau flies. These results reveal the critical role of S5b/PSMD5 in negative regulation of proteasome by TNF-α/NFκB and provide insights into proteasome inhibition in human disease

    Time Series Analysis on the Conformational Change of c-Src Tyrosine Kinase

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    c-Src tyrosine kinase plays an important role in signal transduction pathways, where its activity is regulated by phosphorylation of the two tyrosine residues. We performed targeted molecular dynamics simulation to obtain trajectory of conformational change from inactive to active form. To investigate the conformational change of c-Src tyrosine kinase, we applied network analysis to time series of correlation among residues. The time series of correlation between residues during the conformational change generated by targeted molecular dynamic simulation. With centrality measures such as betweenness centrality, degree centrality, and closeness centrality, we observed a few important residues that significantly contribute to the conformational change of c-Src tyrosine kinase for the different time steps

    Correlation of hypoxia inducible transcription factor in breast cancer and SUVmax of F-18 FDG PET/CT

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    BACKGROUND: Tumor hypoxia induces the expression of several genes via the hypoxia-inducible transcription factor-1 alpha (HIF-1a). It is associated with the prognosis of several cancers. We studied the immunohistochemical expression of HIF-1a in patients with invasive ductal cancer (IDC) of the breast and the possible correlation with the maximum standardized uptake value of the primary tumor (pSUVmax) as well as other biological parameters. Prognostic significance of pSUVmax and expression of HIF-1a for the prediction of progression-free survival (PFS) was also assessed. MATERIAL AND METHODS: Two-hundred seven female patients with IDC who underwent pretreatment fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) were enrolled. The pSUVmax was compared with clinicopathological parameters including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), axillary lymph node (LN) metastasis, stage and HIF-1a expression. The prognostic value of pSUVmax for PFS was assessed using the Kaplan-Meier method. RESULTS: pSUVmax was significantly higher in patients with HIF-1a expression ≥ 2 compared to patients with HIF-1a expression < 2 (5.2 ± 4.5 vs. 3.7 ± 3.1, p = 0.008). pSUVmax was also significantly higher in higher stage (p < 0.000001), ER-negative tumors (p < 0.0001), PR-negative tumors (p = 0.0011) and positive LN metastasis (p = 0.0013). pSUVmax was significantly higher in patients with progression compared to patients who were disease-free (6.8 ± 4.4 vs. 4.1 ± 3.7, p = 0.0005). A receiver-operating characteristic curve demonstrated a pSUVmax of 6.51 to be the optimal cutoff for predicting PFS (sensitivity: 53.6%, specificity: 86.0%). Patients with high pSUVmax (> 6.5) had significantly shorter PFS compared to patients with low pSUVmax (p < 0.0001). CONCLUSIONS: pSUVmax on pretreatment F-18 FDG PET/ CT reflect expression of HIF-1a and can be used as a good surrogate marker for the prediction of progression in patients with IDC. The amount of FDG uptake is determined by the presence of glucose metabolism and hypoxia in breast cancer cell

    Potential effects of sediment processes on water quality of an artificial reservoir in the Asian monsoon region

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    Sediment processes in lakes may affect water chemistry through the internal loading of phosphorus, ammonia, and sulfides released under anoxic conditions. Lake Soyang is a deep warm monomictic reservoir with a dendritic shape, located in the Asian summer monsoon region, South Korea. During summer, the lake is stratified and receives a large nutrient input via storm runoff, which forms a turbid intermediate layer with high concentrations of suspended particles. The lake water, the main inflowing stream (the Soyang River), bottom sediment, and porewater of the lake sediments were studied over a 2-year period (2012–2013). After intensive monsoon rain events, particulate organic carbon (POC), total phosphorus (TP), and turbidity were high in the inflowing water (C: 1.21 mg L−1 in June 2013) and in the metalimnion (2.8 mg L−1, 17.6 μg L−1, and 58.5 NTU, respectively in July 2013). Higher concentrations of iron (Fe) and manganese (Mn) were also associated with the turbid intermediate layer (37 and 8 μg L−1, respectively, in July 2013). During the summer stratification period, oxygen started to deplete in the hypoliminion (down to 0.5 mg L−1 in September 2013), and sediment became anoxic, showing negative oxidation redox potential (ORP) in core samples. Diffusion of dissolved inorganic P and ammonia from sediment to the water column can be substantial, considering the concentration difference between the porewater and hypolimnetic water. Fe and Mn were abundant in the sediment porewater at the dam site, implying inorganic nutrients and minerals are well transported along the 60 km long lake axis by the density current of storm runoff. Sulfate and reduced sulfur were larger in the porewater of the top sediment than in the lower layer of the sediment core (below 10 cm). The results show that substantial amounts of inorganic nutrients and minerals are supplied to the lake by storm runoffs during monsoon and distributed through the lake by a density current, controlling the material cycle and flux at the sediment surface

    E2-25K/Hip-2 regulates caspase-12 in ER stress–mediated Aβ neurotoxicity

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    Amyloid-β (Aβ) neurotoxicity is believed to contribute to the pathogenesis of Alzheimer's disease (AD). Previously we found that E2-25K/Hip-2, an E2 ubiquitin-conjugating enzyme, mediates Aβ neurotoxicity. Here, we report that E2-25K/Hip-2 modulates caspase-12 activity via the ubiquitin/proteasome system. Levels of endoplasmic reticulum (ER)–resident caspase-12 are strongly up-regulated in the brains of AD model mice, where the enzyme colocalizes with E2-25K/Hip-2. Aβ increases expression of E2-25K/Hip-2, which then stabilizes caspase-12 protein by inhibiting proteasome activity. This increase in E2-25K/Hip-2 also induces proteolytic activation of caspase-12 through its ability to induce calpainlike activity. Knockdown of E2-25K/Hip-2 expression suppresses neuronal cell death triggered by ER stress, and thus caspase-12 is required for the E2-25K/Hip-2–mediated cell death. Finally, we find that E2-25K/Hip-2–deficient cortical neurons are resistant to Aβ toxicity and to the induction of ER stress and caspase-12 expression by Aβ. E2-25K/Hip-2 is thus an essential upstream regulator of the expression and activation of caspase-12 in ER stress–mediated Aβ neurotoxicity

    The effects of Asian summer monsoon on algal blooms in reservoirs

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    An important characteristic of lakes and reservoirs in the East Asian summer monsoon region is the dramatic seasonal difference in hydrologic inputs, with annual rainfall commonly concentrated in a few heavy rain events. In this study, we surveyed the monthly variations of phytoplankton density in 3 large deep reservoirs and 7 small shallow reservoirs and analyzed the effect of large precipitation events on phytoplankton. During heavy rains, stream phosphorus concen¬trations increased sharply, and phosphorus loadings into reservoirs were not continuous but episodic shock loadings. In deep stratified reservoirs, however, the concentrations of phosphorus and chlorophyll a were much lower than expected from the high total phosphorus levels in the storm runoff. Inflowing storm waters laden with phosphorus flowed into metalimnetic layers because deep reservoirs had strong thermal stratification and the storm water was cooler than the epilimnion. The result was the formation of an ecosystem resilient to phosphorus shock loadings during monsoon. Nutrients in the metalimnion seemed to be dispersed gradually toward the epilimnion, and phytoplankton reached maximum densities, called “monsoon blooms,” after the monsoon. By contrast, shallow reservoirs with short hydraulic residence times had lower chlorophyll a concentrations during the monsoon season because the high flushing rate was the major limiting factor of phytoplankton growth. In conclusion, summer monsoon is the major determinant of phyto¬plankton density in reservoirs of the East Asian region, but their responses can vary widely depending on hydrologic characteristics
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