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Effects of Fire on Forest Vegetation in Mt. Samma (산불이 삼마산의 삼림식생에 미치는 영향)

  • Kim, Woen;Park, Jung-Hye;Cho, Young-Ho
    • The Korean Journal of Ecology
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    • v.22 no.3
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    • pp.145-153
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    • 1999
  • Authors report the changes of the community structure and secondary succession after fire in Mt. Samma (333 m). Approximately six ha of the red pine (Pinus densiflora) forest and its floor vegetation were burned and cutted down. The vegetation and soil properties were investigated in the burned and unburned sites from April to October, 1998. The dominant species based on SDR₃ in the burned site were Lespedeza cyrtobotrya (96.87), Quercus serrata (77.90), Cyperus amuricus (46.22) and Miscanthus sinensis var. purpurascens (38.33), whereas the dominant species in the unburned site were Pinus densiflora (100.00) and Q. variabilis (66.10) at the tree layer, Q. serrata (100.00) and Zanthoxylum schinifolium (29.64) at the shrub layer., and Q. serrata (76.30) and M. sinensis var. purpurascens (72.84) at the herb layer. The biological spectra based on SDR₃ were Th-D₁-R/sub 5/-e for the burned and H (M)-D₁-R/sub 5/-e type for the unburned site, respectively. The index of similarity (CCs) between the burned and unburned sites was 0.41. The degree of succession (DS) were 609 for the burned and 1168 for the unburned site, respectively. The species diversity (H) and evenness indices (e) of the burned site were lower than those of the unburned site, but the dominance indices (C) was higher in the burned site. In the analysis of soil properties, pH, the content of NO₃/sup -/-N, available phosphrous, and exchangeable cations (K/sup +/, Ca/sup 2+/, Na/sup +/, Mg/sup 2+/) in the burned site were higher than those in the unburned site, whereas the contents of organic matter, total carbon, total nitrogen and NH₄/sup +/-N were lower in the burned site. The results show that dominant species in the burned site change from Miscanthus-Lespedeza→Lespedeza→Quercus and finally to Quercus forest, and the changes of soil properties also affect the early vegetational succession after fire.

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Characteristics of Plant Distribution in the Reclaimed Dredging Area in Gwangyang Bay, Korea

  • Nam, Woong;Kwak, Young-Se;Lee, Deok-Beom;Lee, Sang-Suk
    • Journal of Ecology and Environment
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    • v.32 no.2
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    • pp.115-121
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    • 2009
  • In order to elucidate the mechanisms affecting plant distributions in the reclaimed dredging area in the Gwangyang steelworks, in the Gwangyang Bay, Korea, we examined soil characteristics and plant distributions in four study sites and a control site in the study area. Desalination occurring along a gradient with increasing elevation, resulting in decrease of soil pH, EC, P, K, Cl, Ca, Mg, and salt and an increase in soil T-N, silt, clay contents. From site 1 (the lowest-elevation site) to site 5 (the highest-elevation site), halophytes decreased in abundance and nonhalophytes increased. The dominant species in each site were: Phragmites communis, Limonium tetragonum, and 12 additional species at site 1, Carex pumila, Suaeda japonica, and 15 additional species at site 2, Spergularia marina, Scirpus planiculmis, and 22 additional species at site 3, Miscantus sinensis, Lespedeza bicolor, and 26 additional species at site 4 and Pinus thunberii, Rhododendron mucronulatum, and 39 additional species at site 5, which resembled a naturally-occurring P. thinbergii community. Cluster analysis of the vegetation data matrix grouped the 35 plots into 5 major groups, and cluster analysis using the soil environment data matrix revealed 4 major groups. CCA of the floristic and environmental data matrix showed a positive relationship of SAR, EC, Na, Cl, and Ca, which are related to salt, in the $1^{st}$ axis and $2^{nd}$ axis, but negative relationships for altitude, organic contents, silt, and clay contents. Notably, plant species in the reclaimed dredging area that were separated along the $1^{st}$ axis showed strong relationships with factors that related to salt. Long-term exposure to natural rainfall in the reclaimed dredging area changed the soil characteristics, such as salinity. This change in soil characteristics might alter the SAR, which affects plant survival strategies in a given habitat. These results strongly indicated that factors related to salt and elevation play important roles in determining the overall plant distribution in the reclaimed dredging area.

Valproic Acid Induces Transcriptional Activation of Human GD3 Synthase (hST8Sia I) in SK-N-BE(2)-C Human Neuroblastoma Cells

  • Kwon, Haw-Young;Dae, Hyun-Mi;Song, Na-Ri;Kim, Kyoung-Sook;Kim, Cheorl-Ho;Lee, Young-Choon
    • Molecules and Cells
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    • v.27 no.1
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    • pp.113-118
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    • 2009
  • In this study, we have shown the transcriptional regulation of the human GD3 synthase (hST8Sia I) induced by valproic acid (VPA) in human neuroblastoma SK-N-BE(2)-C cells. To elucidate the mechanism underlying the regulation of hST8Sia I gene expression in VPA-stimulated SK-N-BE(2)-C cells, we characterized the promoter region of the hST8Sia I gene. Functional analysis of the 5'-flanking region of the hST8Sia I gene by the transient expression method showed that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-${\kappa}B$, functions as the VPA-inducible promoter of hST8Sia I in SK-N-BE(2)-C cells. Site-directed mutagenesis and electrophoretic mobility shift assay indicated that the NF-${\kappa}B$ binding site at -731 to -722 was crucial for the VPA-induced expression of hST8Sia I in SK-N-BE(2)-C cells. In addition, the transcriptional activity of hST8Sia I induced by VPA in SK-N-BE(2)-C cells was strongly inhibited by SP600125, which is a c-Jun N-terminal kinase (JNK) inhibitor, and $G{\ddot{O}}6976$, which is a protein kinase C (PKC) inhibitor, as determined by RT-PCR (reverse transcription-polymerase chain reaction) and luciferase assays. These results suggest that VPA markedly modulated transcriptional regulation of hST8Sia I gene expression through PKC/JNK signal pathways in SK-N-BE(2)-C cells.

Long-term Seasonal and Interannual Variability of Epilimnetic Nutrients (N, P), Chlorophyll-a, and Suspended Solids at the Dam Site of Yongdam Reservoir and Empirical Models

  • An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.44 no.2
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    • pp.214-225
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    • 2011
  • The objectives of the study were to evaluate seasonal patterns of epilimnetic water quality, and determine interannual eutrophication patterns at the dam site of Yong-dam Reservoir using long-term data during 2002~2009. Ionic dilutions, based on specific conductivity, occurred in the summer period in response to the intense monsoon rain and inflow, and suspended solid analysis indicated that the reservoir was clear except for the monsoon. Seasonality of nitrogen contents varied depending on the types of nitrogen and responded to ionic dilution; Ammonia-nitrogen ($NH_4$-N) peaked at dry season but nitrate-nitrogen ($NO_3$-N) peaked in the monsoon when the ionic dilution occurred. The maxima of $NO_3$-N seemed to be related with external summer N-loading from the watershed and active nitrogen fixation of bluregreens in the summer. $NO_3$-N was major determinant (>50%) of the total nitrogen pool and relative proportion of $NH_4$-N was minor. Long-term annual $NO_3$-N and TDN showed continuous increasing trends from 2004 to 2009, whereas TP and TDP showed decreasing trends along with chlorophyll-a (CHL) values. Empirical model analysis of log-transformed nutrients and N : P ratios on the CHL showed that the reservoir CHL had a stronger linear function with TP ($R^2$=0.89, p<0.001) than TN ($R^2$=0.35, p=0.120). Overall results suggest that eutrophication progress, based on TP and CHL, is slow down over the study period and this was mainly due to reduced phosphorns, which is considered as primary nutrient by the empirical model.

Extrapulmonary Small Cell Carcinoma - a Case Series of Oropharyngeal and Esophageal Primary Sites Treated with Chemo-Radiotherapy

  • Sahai, Puja;Baghmar, Saphalta;Nath, Devajit;Arora, Saurabh;Bhasker, Suman;Gogia, Ajay;Sikka, Kapil;Kumar, Rakesh;Chander, Subhash
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.16
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    • pp.7025-7029
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    • 2015
  • Background: The optimal sequence and extent of multimodality therapy remains to be defined for extrapulmonary small cell carcinoma because of its rarity. The purpose of our study was to assess the response to neoadjuvant chemotherapy followed by chemoradiation/radiation in patients with extrapulmonary small cell carcinoma. Materials and Methods: Four consecutively diagnosed patients were included in this study. The primary tumor site was oropharynx in three patients and esophagus in one. The patients with the limited disease were treated with chemotherapy followed by concurrent chemoradiation (n=2) or radiotherapy (n=1). The patient with the extensive disease with the primary site in vallecula was treated with chemotherapy and palliative radiotherapy to the metastatic site. Results: The median follow-up was 22.5 months (range, 8-24 months). Three patients with the limited disease (base of tongue, n=2; esophagus, n=1) were in complete remission. The patient with the extensive disease died of loco-regional tumor progression at 8 months from the time of diagnosis. Conclusions: The combination of chemotherapy and radiotherapy is the preferred therapeutic approach for patients with extrapulmonary small cell carcinoma. Induction chemotherapy followed by concurrent chemoradiation or radiation provides a good loco-regional control in patients with limited disease.

Biogenic Particulate Matter Accumulation in Peter the Great Bay, East Sea (Japan Sea)

  • Hong, Gi-Hoon;Park, Sun-Kyu;Chung, Chang-Soo;Kim, Suk-Hyun;Tkalin, Alexander V.;Lishavskaya, Tatiana S.
    • Journal of the korean society of oceanography
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    • v.31 no.3
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    • pp.134-143
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    • 1996
  • Sediment cores were collected from one site each in Amursky and Ussuriysky Bays in the Peter the great Bay for $^{210}Pb$, org C, N, biogenic Si, ${\delta}^{13}$C and ${\delta}^{15}$N analysis to elucidate the processes of biogenic particulate matter accumulation and early diagenetic change in the upper sediment column. Biogeochemistry at the core sites of both bays shows differences in sedimentation rate, sediment mixing, and diagenetic processes of particulate biogenic matter. Sedimentary organic matter at the core sites in both bays appeared to be largely derived from marine origin. Sedimentation rates are 173 and 118 mg $cm^{-2}$ $yr^{-1}$(0.13 and 0.11 cm $yr^{-1}$) in Amursky and Ussuriysky Bays, respectively. The surface mixed layer in the core top was present in Amursky Bay but not in Ussuriysky Bay. At the core site in Amursky Bay, incorporation of biogenic particulate matter into the sediment from the overlying waters is 236, 19, 142 mmol $cm^{-2}$ $yr^{-1}$ for organic C, N, and biogenic Si, respectively. Of which about 70${\%}$ of organic C and biogenic Si are degraded within the upper 25 cm sediment and the rest are buried at 25 cm sediment horizon. At the core site in Ussuriysky Bay, incorporation of biogenic particulate matter into the sediment from overlying waters is 164, 18, 76 mmol $cm^{-2}$ $yr^{-1}$ for organic C, N, and biogenic Si, respectively. Of which less than 50${\%}$ of organic C and biogenic Si are degraded within the upper 25 cm sediment and the remainder are buried at 25 cm sediment horizon. This large difference of degradation of biogenic matter in the upper 25 cm sediment column appears to be resulted from the difference in sediment mixing rates between the two cores.

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Investigation on soil contamination and its remediation system in the vicinity of abandoned Au-Ag mine in Korea (휴/폐광 금은광산 주변의 토양오염조사와 복구시스템 연구)

  • 정명채
    • Economic and Environmental Geology
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    • v.32 no.1
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    • pp.73-82
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    • 1999
  • The objectives of this study are to investigate soil contamination in the vicinity of abandoned Au-Ag mine and to apply a remediation technique of liming to tailings. In the study area of the Imcheon Au-Ag mine, soils were sampled in and around the mine the analyzed by Atomic Absorption Spectrometry extracted by both 0.1N HCl and aqua regia. Elevated levels of Cd, Cu, Pb and Zn concentrations extracted by 0.1N HCl were found in soils taken from tailings site. These high contents directly influenced metal concentrations in soils taken in the vicinity of the site. This is mainly due to clastic movement by wind and effluent of mine waste water. In addition, relatively enriched concentrations of the metals were found in soils extrated by aqua regia due to strong decomposition of the samples compared with 0.1N HCl extration. According to the statistical approach, metal concentrations in soils by 0.1N HCl had a positive correlation with those by aqua regia extraction. Mine waste waters and stream waters were also sampled around the mine in spring and summer and analyzed by AAS for Cd, Cu, Pb and Zn, and by Ion Chromatography for anions. Like soils developed over tailings, significant levels of metals and sulphates were found in the mine waste waters ranging of 0.2~0.3, 0.5~2.0, 0.2~2.8, 30~50 and 1,240~4,700 mg/l of Cd, Cu, Pb, Zn and $SO_4^{2-}$, respectively. These elevated levels influenced in the stream waters in the vicinity of the tailings site. In seasonal variation of metal and anion contents, relatively high levels were found in waters sampled on summer due to leaching the metals and anions from tailings by rain. This study also examined the possibility of lime treatment for remediation of acid mine tailings and assumed to be 46 tones of pulverized lime for neutralization of the tailings.

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Identification of a Potential Tyrosine Phosphorylation Site on the NR2B Subunit of the N-methyl-D-aspartate Receptor (NMDA 수용체 아단위 2B의 Tyrosine 인산화 위치의 동정)

  • Il Soo Moon;Yong Wook Jung;Bok Hyun Ko
    • Journal of Life Science
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    • v.8 no.6
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    • pp.654-659
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    • 1998
  • The 2B subunit of N-methyl-D-aspartate (NMDA) receptors (NR2B) is the major phosphotyrosine-containing pro-tein in the postsynaptic density (PSD). In order to identify the site for tyrosine phosphorylation on NR2B, a mass spectrometry was applied on tryptic and endolys-C peptides. The NR2B subunit was isolated from N-octyl glucoside (NOG)-insoluble PSD fraction through SDS-PAGE and electroelution. The eluted protein was confirmed to be NR2B and phosphorylated on tyrosine by its cognate antibody and phosphotyrosine-specific antibody. By matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry of the peptides generated by digesting the eluted NR2B with trysin or endolys-C, a potential site for tyrosine phosphorylation could be identified as Tyr-1304.

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Abdominal Inflammatory Myofibroblastic Tumor in Children (소아에서 발생한 복강내 염증성 근섬유모세포종의 임상적 고찰)

  • Kim, Hyun-Young;Moon, Suk-Bae;Jung, Sung-Eun;Lee, Seong-Cheol;Park, Kwi-Won;Kim, Woo-Ki
    • Advances in pediatric surgery
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    • v.14 no.2
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    • pp.153-163
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    • 2008
  • Inflammatory myofibroblastic tumor (IMT) is a rare reactive lesion characterized by the feature of myofibroblasts and a mixed inflammatory infiltrate that rarely undergoes malignant transformation. Extrapulmonary IMTs in children have been described involving the mesentery, omentum, retroperitoneum, abdominal soft tissues, liver, bladder, mediastinum, head and neck, extremity, appendix, and kidney. Medical records of children treated with abdominal IMT between 1985 and 2005 were reviewed retrospectively. Seven children were treated for IMT with the mean age of 3 y 2 m (range, 1 y 1 m to 14 y). Tumors were located in transverse mesocolon (n=2), omentum (n=1), porta hepatis (n=2), complex site (antrum, duodenum, common bile duct, porta hepatis) (n=2). The symptoms included abdominal mass, fever, jaundice, abdominal pain and anemia. The masses were excised totally in transverse mesocolon, omentum IMT and there is no evidence of recurrence (follow-up periods: 6 y 8 m, 8 y 9 m, 4 y 10 m). In porta hepatis IMT, liver transplantations were performed and there is no evidence of recurrence (follow period: 6 y 8 m, 8 y 7 m). In one case of complex site IMT, partial excision of mass was performed and he still survived with no change of the residual tumor during follow-up period. The other one of complex site IMT denied further treatment after the biopsy. In conclusion, complete surgical excision including liver transplantation and close follow-up are mandatory for the abdominal IMT in child.

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