• Economic and Environmental Geology
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• v.44 no.6
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• pp.463-474
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• 2011

The Haenam epithermal mineralized zone is located in the southwestern part of South Korea, and hosts low sulfidation epithermal Au-Ag deposit (Eunsan-Moisan) and clay quarries (Okmaesan, Seongsan, and Chunsan). Epithermal deposits and accompanying hydrothermal alteration related to Cretaceous volcanism caused large zoned assemblages of hydrothermal alteration minerals. Advanced argillic-altered rocks with mineral assemblages of alunite-quartz, alunite-dickite-quartz, and dickite-kaolinite-quartz exposed on the Okmaesan, Seongsan, and Chunsan area. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), with three visible and near infrared bands, six shortwave infrared bands, and five thermal infrared bands, was used to identify advanced argillic-altered rocks within the Haenam epithermal mineralized zone. The distinct spectral features of hydrothermal minerals allow discrimination of advanced argillic-altered rocks from non-altered rocks within the study area. Because alunite, dickite, and kaolinite, consisting of advanced argillic-altered rocks within the study area are characterized by Al-O-H-bearing minerals, these acid hydrothermal minerals have a strong absorption feature at $2.20{\mu}m$. The band combination and band ratio transformation cause increasing differences of DN values between advanced argillic-altered rock and non-altered rock. The alunite and dickite-kaolinite of advanced argillic-altered rocks from the Okmaesan, Seongsan, and Chunsan have average DN values of 1.523 and 1.737, respectively. These values are much higher than those (1.211 and 1.308, respectively) of non-altered area. ASTER images can remotely provide the distribution of hydrothermal minerals on the surface. In this way good relation between ASTER spectra analysis and field data suggests that ASTER spectral analysis can be useful tool in the initial steps of mineral exploration.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.92-100
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• 2013

Purpose: To investigate the clinicopathologic effects of cyclosporine A (CsA) in children with diseases characterized by mesangial immunoglobulin A deposits such as immunoglobulin A nephropathy (IgAN) and Henoch-Sch$\ddot{o}$nlein purpura nephritis (HSPN). Methods: We retrospectively reviewed the clinicopathologic outcomes of 54 children (IgAN, 36; HSPN, 18) treated with CsA. The starting dose of CsA was 5 mg/kg per day, and it was administered in 2 divided doses. The degree of proteinuria and pathologic changes in renal biopsies were evaluated before and after CsA treatment. Results: The mean protein to creatinine ratio decreased from $3.7{\pm}1.5$ to $0.6{\pm}0.4$(P <0.001), and 32 (59.2%) children achieved complete remission of proteinuria after 1-year CsA treatment. Among the 54 children, 24 maintained normal renal function and 25 exhibited microscopic hematuria or proteinuria at the end of CsA treatment. In the HSPN group, 3 children whose initial biopsies indicated class IIIb disease showed class II disease on follow-up, and the follow-up biopsies of 2 children who had class II disease indicated the same class II disease. In the IgAN group, cortical tubular atrophy occurred in 1 child, and no child with IgAN had cortical interstitial fibrosis or tubular atrophy after 1-year CsA treatment. No significant complications were found in the children treated with CsA. Conclusion: Our findings indicate that CsA treatment is effective and beneficial in reducing massive proteinuria and preventing progression to end-stage renal failure in children with glomerular diseases characterized by IgA deposits, such as IgAN and HSPN, within 1 year of treatment.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.380-389
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• 2007

Stable carbon and nitrogen isotopes were analyzed in suspended particulate organic matter, macroalgae and macrobenthic invertebrates in order to determine the importance of primary organic matter sources in supporting food webs of rocky subtidal and intertidal macroalgal beds in the Korean coasts. Investigations were conducted at the inter tidal sites within Gwangyang bay, a semi-enclosed and eutrophicated bay, and the subtidal sites of the east coast, a relatively oligotrophic and open environment, in May and June 2005. Water-column suspension feeders showed more negative $\delta^{13}C$ values than those of the other feeding guilds, indicating trophic linkage with phytoplankton and thereby association with pelagic food chains. In contrast, animals of the other feeding guilds, including interface suspension feeders, herbivores, deposit feeders, omnivores and predators, displayed relatively less negative $\delta^{13}C$ values than those of the water-column suspension feeders and similar with that of macroalgae, indicating exclusive use of macroalgae-derived organic matter and association with benthic food chains. Most the macrobenthic species were considered to form strong trophic links with benthic food chains. In addition, the distribution of higher $\delta^{15}N$ values in macrobenthic consumers and macroalgae at the intertidal sites of Gwangyang Bay than those at the subtidal sites of the east coast suggests that anthropogenic nutrients may enhance the macroalgal production at the intertidal sites and in turn be incorporated into the particular littoral food web in Gwangyag Bay. These results confirm the dominant role of macroalgae in supporting rocky subtidal and intertidal food webs in the Korean coasts.