2,807 research outputs found

    EUTROPHICATION OF THE MAJOR RESERVOIRS IN KOREA

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    Trophic state of several major reservoirs in Korea are reviewed. Most of large reservoirs are mesotrophic to eutrophic, suffering bluegreen algal blooms. Recently many reservoirs are being eutrophied at high rate mainly due to the increase of excretion by livestock in watershed and netcage-type fishfarms within the lake basins. The trophic state changes of Lake Soyang, from oligotrophy to eutrophy in recent 10 years, are presented as a case study of rapid eutrophication. Chlorophyll a concentration increased from ca. 3mg/m³ in early 1980s to 15 mg/m³ in 1989. The dominant phytoplankton species in summer are changed from Peridinium to Anabaena since 1986 and the standing crop of Anabaena has been increasing. Secchidisc depth decreased from 5 to 1m. TP increased from 7 to 20 mgP/m³. The rate of hypolimnetic oxygen deficit increased year to year from 0.028 mgO₂/cm²/day in 1986 to 0.094 in 1989. Fishfarms within the lake are the major phosphorus source in Lake Soyang exceeding the total phosphorus loading from the watershed. This high rate of eutrophication is expected to persist in next decade.Article信州大学理学部付属諏訪臨湖実験所報告 7: 21-29(1991)departmental bulletin pape

    Observational Evidence of EHP Effects on the Melting of Snowpack over the Tibetan Plateau

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    Observational evidences are presented showing that the Indo-Gangetic Plain (IGP) regions, bounded by the high altitude Himalayan mountains, are subject to heavy loading of absorbing aerosols, i.e., black carbon and dust, which can lead to widespread enhancement warming over the Tibetan Plateau and accelerated snowmelt in the western Tibetan Plateau (WTP) and Himalayas. The two pre-monsoon seasons of 2004 and 2005 were strikingly contrasting in terms of the aerosol loading over IGP. The warming of the TP in 2004 relative to 2005 was widespread, covering most of the WTP and Himalayas. This warming is closely linked to patterns of the snow melt. Consistent with the Elevated Heat Pump hypothesis, we find that increased loading of absorbing aerosols over IGP in the pre-monsoon season is associated with increased heating of the upper troposphere by dynamical feedback induced by aerosol heating, and enhances the rate of snowmelt over Himalayas and the WTP in April-May. Composite analysis with more contrasting years also shows that the heating of the troposphere by elevated dust and black carbon aerosols in the boreal spring can lead to widespread enhanced land-atmosphere warming, and accelerated snow melt in the Himalayas and Tibetan Plateau

    The C-terminal region of Bfl-1 sensitizes non-small cell lung cancer to gemcitabine-induced apoptosis by suppressing NF-κB activity and down-regulating Bfl-1

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    Gemcitabine is used to treat several cancers including lung cancer. However, tumor cells often escape gemcitabine-induced cell death via various mechanisms, which include modulating bcl-2 family members and NF-κB activation. We previously reported that the C-terminal region of Bfl-1 fused with GFP (BC) is sufficient to induce apoptosis in 293T cells. In the present study, we investigated the anti-tumor effect of combined BC gene therapy and gemcitabine chemotherapy in vitro and in vivo using non-small cell lung cancer cell lines and a xenograft model. Cell lines were resistant to low dose gemcitabine (4-40 ng/ml), which induced NF-κB activation and concomitant up-regulation of Bfl-1 (an NF-κB-regulated anti-apoptotic protein). BC induced the apoptosis of A549 and H157 cells with caspase-3 activation. Furthermore, co-treatment with BC and low dose gemcitabine synergistically and efficiently induced mitochondria-mediated apoptosis in these cells. When administered alone or with low dose gemcitabine, BC suppressed NF-κB activity, inhibited the nuclear translocation of p65/relA, and down-regulated Bfl-1 expression. Furthermore, direct suppression of Bfl-1 by RNA interference sensitized cells to gemcitabine-induced cell death, suggesting that Bfl-1 importantly regulates lung cancer cell sensitivity to gemcitabine. BC and gemcitabine co-treatment also showed a strong anti-tumor effect in a nude mouse/A549 xenograft model. These results suggest that lung cancer cells become resistant to gemcitabine via NF-κB activation and the subsequent overexpression of Bfl-1, and that BC, which has both pro-apoptotic and NF-κB inhibitory effects, could be harnessed as a gene therapy to complement gemcitabine chemotherapy in non-small cell lung cancer

    Avifauna of Bangtaesan Mountain, Gangwon-do, Korea

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    AbstractAn investigation on avifauna of the Bangtaesan Mountain was carried out from February until November, 2010 and it drew the results as follow. The number of birds observed in the whole Bangtaesan Mountain region was 989 individuals of 51 species (Maximum counts). Considering the results from literature research in addition, at least 90 species 1,000 individuals are thought to live in this region. In result, dominant species proved to be Yellow-throated Bunting (Emberiza elegans), Marsh Tit (Parus palustris), Azure-winged Magpie (Cyanopica cyana), Eastern Crowned Willow Warbler (Phylloscopus coronatus), Varied Tit (Parus varius), and more. Most of birds breeding in the forest of Korea were found to constitute these dominant bird species. Entire species diversity index appeared to be 3.35 relatively a high level; 3.34 in the south slopes while 3.22 in the north slopes showing relatively a high level in the south. Of them, 12 species including Mandarin Duck (Aix galericulata) were the Protected Birds species nominated and protected by the Cultural Heritage Administration or the Ministry of Environment, while 10 and 6 species were the natural monument species and endangered species level, respectively. Should further consistent surveys be carried out, a broader range of species would be found to breed, and therefore the Bangtaesan Mountain region including the area where the protected species are observed is believed to need a conservation and management through protected area designation

    Metal-organic framework based on hinged cube tessellation as transformable mechanical metamaterial

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    Mechanical metamaterials exhibit unusual properties, such as negative Poisson???s ratio, which are difficult to achieve in conventional materials. Rational design of mechanical metamaterials at the microscale is becoming popular partly because of the advance in three-dimensional printing technologies. However, incorporating movable building blocks inside solids, thereby enabling us to manipulate mechanical movement at the molecular scale, has been a difficult task. Here, we report a metal-organic framework, self-assembled from a porphyrin linker and a new type of Zn-based secondary building unit, serving as a joint in a hinged cube tessellation. Detailed structural analysis and theoretical calculation show that this material is a mechanical metamaterial exhibiting auxetic behavior. This work demonstrates that the topology of the framework and flexible hinges inside the structure are intimately related to the mechanical properties of the material, providing a guideline for the rational design of mechanically responsive metal-organic frameworks

    Single incision thoracoscopic right upper lobectomy with systematic lymph node dissection

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    Video-assisted thoracic surgery (VATS) provides less postoperative pain, preservation of the immune response and shorter recovery period, compared with thoracotomy. However, many patients complain of postoperative pain and paresthesia because VATS requires 3 or 4 incisions including a utility incision of 3–5 cm. To overcome this problem, single incision thoracoscopic surgery has emerged; this technique has been adopted for lung cancer surgery since 2010. Complete mediastinal lymph node dissection is the major role of lung cancer surgery. We describe a case of a right upper lobectomy with complete mediastinal lymph node dissection via single incision thoracosopic surgery

    Pixel-wise Guidance for Utilizing Auxiliary Features in Monte Carlo Denoising

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    Auxiliary features such as geometric buffers (G-buffers) and path descriptors (P-buffers) have been shown to significantly improve Monte Carlo (MC) denoising. However, recent approaches implicitly learn to exploit auxiliary features for denoising, which could lead to insufficient utilization of each type of auxiliary features. To overcome such an issue, we propose a denoising framework that relies on an explicit pixel-wise guidance for utilizing auxiliary features. First, we train two denoisers, each trained by a different auxiliary feature (i.e., G-buffers or P-buffers). Then we design our ensembling network to obtain per-pixel ensembling weight maps, which represent pixel-wise guidance for which auxiliary feature should be dominant at reconstructing each individual pixel and use them to ensemble the two denoised results of our denosiers. We also propagate our pixel-wise guidance to the denoisers by jointly training the denoisers and the ensembling network, further guiding the denoisers to focus on regions where G-buffers or P-buffers are relatively important for denoising. Our result and show considerable improvement in denoising performance compared to the baseline denoising model using both G-buffers and P-buffers.Comment: 19 page
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