651 research outputs found

    New Model of Productive Online Discussion and Its Implications for Research and Instruction

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    We develop a new model of productive online discussion based on a brief review of research literature on online discussion. As compared to previous discussion models, the new model provides a more systematic and comprehensive framework to understand how learning occurs through online discussion. Based on the new model, we propose several directions for research on improving the quality of online discussion and learning

    A New Model of Productive Online Discussion and Its Implications for Research and Instruction

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    We develop a new model of productive online discussion based on a brief review of research literature on online discussion. As compared to previous discussion models, the new model provides a more systematic and comprehensive framework to understand how learning occurs through online discussion. Based on the new model, we propose several directions for research on improving the quality of online discussion and learning

    Public administration research in mainland China and Taiwan: an assessment of journal publications, 1998-2008

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    10.1111/j.1467-9299.2011.01978.xPublic Administration912261-28

    Postoperative anatomical and functional outcomes of different stages of high myopia macular hole

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    Background Recently it was suggested that high myopia macular holes (HMMH) and macular holes accompanied by retinal detachment occur in the advanced stages of myopia traction maculopathy (MTM), while macular retinoschisis, shallow retinal detachment without holes, and lamellar macular holes occur in the early stages of MTM. Complete vitreous cortex removal associated with internal limiting membrane peeling is now widely used to treat HMMH. However, it remains uncertain at what HMMH stage patients would benefit most from surgical intervention. Our study was aimed to evaluate the postoperative anatomical changes and functional outcomes of high myopia macular holes (HMMH). Methods Patients were retrospectively collected between March 2009 and August 2011. Before and 1st, 3rd, and 9th month after 23G pars plana vitrectomy, all patients underwent a complete ophthalmologic examination, spectral domain optical coherence tomography (SD-OCT) and MP-1. At each follow-up, best- corrected visual acuity (BCVA), photoreceptor inner and outer segments (IS/OS) defects, and retinal sensitivity (RS) were investigated. According to different preoperative macular hole morphologies, patients were divided into three groups: Group 1, macular hole with epiretinal membrane (ERM) traction and macular retinoschisis; Group 2, full-thickness macular hole (FTMH); Group 3, FTMH with subretinal fluid. Results 43 eyes from 43 patients met the inclusion criteria. The mean age was 60 years. BCVA and RS were significantly improved after vitrectomy; the mean IS/OS defect was significantly reduced. At 9 postoperative months, 11 of 43 (25.6 %) eyes achieved IS/OS junction integrity; 9 of these 11 (81.8 %) eyes belonged to Group 1, 2 (18.2 %) belonged to Group 2. Conclusions Pars plana vitrectomy combined with ILM peeling and gas tamponade results in limited functional outcomes in patients with HMMH. The appearance of subretinal fluid indicates a worse prognosis for surgical intervention

    Profiles of cyclin B and cdc2 during ovarian and embryonic development in <em>Exopalaemon carinicauda</em>

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    Mitosis-promoting factor (MPF) is a complex formed by cyclin B (cyclin B) and cyclin-dependent kinase (cdc2). To investigate the role of MPF in the reproduction of Exopalaemon carinicauda, we cloned its full-length cDNA of the Ec-cyclin B and Ec-cdc2 genes. We analyzed their molecular characteristics and expression profiles during ovarian and embryonic development. The results showed that the Ec-cyclin B gene was 1194 bp long and encoded a 397 amino acid (aa) long protein. However, Ec-cdc2 was 900 bp long, which encoded 299 aa with a conserved cyclin binding motif PSTAIRE. The phylogenetic tree analysis showed that Ec-cyclin B had the highest homology with the cyclin B of Macrobrachium rosenbergii (81.06%). In comparison, Ec-cdc2 had the highest homology with the cdc2 of E. modestus (96.80%). Ec-cyclin B showed the highest expression in the ovary, whereas Ec-cdc2 was the highest in the hepatopancreas, followed by the ovary. In the five stages of ovarian development, Ec-cyclin B and Ec-cdc2 expression levels reach the highest at stage Ⅴ(p < 0.05). Overall, the expression of these two genes first increased and then decreased at different embryonic developmental stages. Therefore, these findings suggested that cyclin B and cdc2 played an essential role in the ovarian and embryonic development of E. carinicauda

    Dynamic post-earthquake image segmentation with an adaptive spectral-spatial descriptor

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    The region merging algorithm is a widely used segmentation technique for very high resolution (VHR) remote sensing images. However, the segmentation of post-earthquake VHR images is more difficult due to the complexity of these images, especially high intra-class and low inter-class variability among damage objects. Herein two key issues must be resolved: the first is to find an appropriate descriptor to measure the similarity of two adjacent regions since they exhibit high complexity among the diverse damage objects, such as landslides, debris flow, and collapsed buildings. The other is how to solve over-segmentation and under-segmentation problems, which are commonly encountered with conventional merging strategies due to their strong dependence on local information. To tackle these two issues, an adaptive dynamic region merging approach (ADRM) is introduced, which combines an adaptive spectral-spatial descriptor and a dynamic merging strategy to adapt to the changes of merging regions for successfully detecting objects scattered globally in a post-earthquake image. In the new descriptor, the spectral similarity and spatial similarity of any two adjacent regions are automatically combined to measure their similarity. Accordingly, the new descriptor offers adaptive semantic descriptions for geo-objects and thus is capable of characterizing different damage objects. Besides, in the dynamic region merging strategy, the adaptive spectral-spatial descriptor is embedded in the defined testing order and combined with graph models to construct a dynamic merging strategy. The new strategy can find the global optimal merging order and ensures that the most similar regions are merged at first. With combination of the two strategies, ADRM can identify spatially scattered objects and alleviates the phenomenon of over-segmentation and under-segmentation. The performance of ADRM has been evaluated by comparing with four state-of-the-art segmentation methods, including the fractal net evolution approach (FNEA, as implemented in the eCognition software, Trimble Inc., Westminster, CO, USA), the J-value segmentation (JSEG) method, the graph-based segmentation (GSEG) method, and the statistical region merging (SRM) approach. The experiments were conducted on six VHR subarea images captured by RGB sensors mounted on aerial platforms, which were acquired after the 2008 Wenchuan Ms 8.0 earthquake. Quantitative and qualitative assessments demonstrated that the proposed method offers high feasibility and improved accuracy in the segmentation of post-earthquake VHR aerial images

    Regression-based approach for testing the association between multi-region haplotype configuration and complex trait

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    <p>Abstract</p> <p>Background</p> <p>It is quite common that the genetic architecture of complex traits involves many genes and their interactions. Therefore, dealing with multiple unlinked genomic regions simultaneously is desirable.</p> <p>Results</p> <p>In this paper we develop a regression-based approach to assess the interactions of haplotypes that belong to different unlinked regions, and we use score statistics to test the null hypothesis of non-genetic association. Additionally, multiple marker combinations at each unlinked region are considered. The multiple tests are settled via the <it>minP </it>approach. The <it>P </it>value of the "best" multi-region multi-marker configuration is corrected via Monte-Carlo simulations. Through simulation studies, we assess the performance of the proposed approach and demonstrate its validity and power in testing for haplotype interaction association.</p> <p>Conclusion</p> <p>Our simulations showed that, for binary trait without covariates, our proposed methods prove to be equal and even more powerful than htr and hapcc which are part of the FAMHAP program. Additionally, our model can be applied to a wider variety of traits and allow adjustment for other covariates. To test the validity, our methods are applied to analyze the association between four unlinked candidate genes and pig meat quality.</p

    Using proteomic analysis to investigate uniconazole-induced phytohormone variation and starch accumulation in duckweed (Landoltia punctata)

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    KEGG pathway analysis of the annotated proteins. The pathway, number of annotated proteins, and pathway ID were listed in the table. (XLSX 15 kb
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