• Ocean and Polar Research
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• 제28권4호
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• pp.475-484
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• 2006

In order to reveal the vertical variation of physical properties in deep-sea sediments, deep-sea sediment cores were collected at 78 stations using a multiple corer in the KR5 area, one of the Korea contract areas for manganese nodule exploration, located in the northeast equatorial Pacific. Based on the color of sediments, sampled sediment cores were characterized into three lithologic units (unit 1,2, and 3). In all sediment cores, three units appear systematically; unit 1 lies at the top of cores and unit 2 and/or unit 3 appear to underlie unit 1 or alternate with unit 3. Unit 1 layer from the top of cores shows dark grayish brown to dark brown with mean thickness of 10.2cm. Unit 2 and 3 layers show very dark brown to black color and yellowish brown to brown color, respectively. According to the physical properties of the deep-sea sediment cores, sediment column can be divided into three sections. Section A $(0{\sim}15cm)$ in subbottom depth consists mostly of unit 1. Mean values of physical properties of section B $(15{\sim}30cm)$ in subbottom depth are similar to those of section C (>30 cm) in subbottom depth. However, the physical properties of section B were more variable than those of section C because of the high activity of bioturbation in section B. These results will provide valuable information for selecting suitable sites for mining manganese nodules in the Korea contract areas.

• 한국환경과학회지
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• 제24권7호
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• pp.893-905
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• 2015

This study analyzes the correlation between Western Pacific (WP) teleconnection pattern index (WPI) in April during 1954-2008 and rainfall amounts in the same month. Based on the results, it is identified that there have been strong positive correlations between central China, Korea and the southwestern part of Japan in the East Asian region. Through differences between 10 positive WP years and 10 negative WP years selected from the April WPI excluding ENSO years, it is found that rainfall amounts increase in April of positive WP years due to the following characteristics. Increases in rainfall amounts are evident in the East Asian middle latitudinal region where the positive correlation between the two variables is the highest and this is because anomalous southwesterlies are strengthened in the East Asian middle latitudinal region due to the spatial pattern of a south-low-north-high anomalous pressure system centered on this region that is made by anomalous anticyclones centered on the southeastern side of the region and other anomalous anticyclones centered on the northeastern side of the region. In addition, anomalous westerlies (jet) are strengthen in the upper troposphere of the East Asian middle latitudinal region and as a result, anomalous upward flows are strengthened in this region and thus anomalous warm air temperatures are formed in the entire level of the troposphere in the region. In addition to atmospheric environments, anomalous warm sea surface temperatures are formed in the seas in the East Asian middle latitudinal region to help the rainfall amount increases in the East Asian middle latitudinal region.

• Ocean and Polar Research
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• 제31권1호
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• pp.11-29
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• 2009

Variability of sea surface temperature (SST) in the Japan/East Sea (JES) was studied using complex empirical orthogonal function (CEOF) analysis. Two daily data sets were analyzed: (1) New Generation 0.05o-gridded SST from Tohoku University, Japan (July 2002-July 2006), and (2) 0.25o-gridded SST from the Japan Meteorological Agency (October 1993-November 2006). Linkages with wind stress curl were revealed using 6-h 1o-gridded surface zonal and meridional winds from ancillary data of the Sea- WiFS Project, a special National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) product (1998-2005). SST anomalies (SSTA) were obtained by removing the seasonal signal, estimated as the leading mode of the CEOF decomposition of the original SST. Leading CEOF modes of residual SSTA obtained from both data sets were consistent with each other and were characterized by annual, semiannual, and quasi-biennial time scales estimated with 95% statistical significance. The Semiannual Mode lagged 2 months behind the increased occurrence of the anticyclonic (AC) wind stress curl over the JES. Links to dynamic processes were investigated by numerical simulations using an oceanic model. The suggested dynamic forcings of SSTA are the inflow of subtropical water into the JES through the Korea Strait, divergence in the surface layer induced by Ekman suction, meridional shifts of the Subarctic Front in the western JES, AC eddy formation, and wind-driven strengthening/weakening of large-scale currents. Events of west-east SSTA movement were identified in July-September. The SSTA moved from the northeastern JES towards the continental coast along the path of the westward branch of the Tsushima Current at a speed consistent with the advective scale.

• 한국해양학회지:바다
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• 제13권3호
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• pp.178-189
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• 2008

2003년 7월, 2005년 8월 그리고 2007년 7월에 북동태평양의 발산대 해역($7^{\circ}{\sim}10.5^{\circ}N$)에서 무기영양염 분포와 재무기질화 비율 연구를 위한 조사를 수행하였다. 북적도 반류와 북적도 해류의 경계에서 형성되는 발산대는 라니냐 현상이 있었던 2007년 7월에 북위 $10^{\circ}N$에 위치하였으며, 용승 현상이 강하게 일어났다. 빈영양 환경의 특성을 갖는 표면 혼합층의 깊이는 2003년에 평균 46 m, 2005년에 평균 61 m 그리고 2007년에 평균 30 m 이었고, 표면 혼합층 이하에서는 용존산소 소모와 더불어 무기영양염 농도가 급격하게 증가하는 영양염약층이 형성됐다. 상층(수심 $0{\sim}100m$)에서 아질산염을 포함한 질산염의 총량은 2003년에 $5.51{\sim}21.71gN/m^2$(평균 $12.82gN/m^2$)의 범위를 나타냈고, 2005년에는 $5.62{\sim}8.46gN/m^2$(평균 $7.15gN/m^2$)의 범위를 그리고 2007년에는 $8.98~27.80 gN/m2$(평균 21.12 gN/m2)의 범위로 발산대가 형성된 지점에서 높은 값을 나타냈다. 인산염 총량과 규산염 총량 또한 아질산염을 포함한 질산염 총량 분포와 유사하였으며, 상층에서 파악된 아질산염을 포함한 질산염 총량에 대한 규산염 총량의 비율은 $0.87{\pm}0.11$ 이었다. 연구 해역에서 식물 플랑크톤 성장을 제한하는 무기영양염은 질소계 영양염으로(N/P ratio=14.6), 북적도 반류 지역에 비해 북적도 해류 지역에서 보다 낮은 농도를 나타냈다. 규산염 또한 낮은 농도로 존재하여 규소 제한 환경을 이루었다. 본 연구를 통해 분석된 재무기질화 비율은 $P/N/-O_2=1/14.6{\pm}1.1/100.4{\pm}8.8(23.44{\leq}Sigma-{\theta}{\leq}26.38)$로 Redfield stoichiometry($P/N/-O_2=1/16/138$) 보다는 낮았지만, 연구 해역 표층에서 재무기질화 과정을 설명하기에 충분하였다.

• 한국해양학회지:바다
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• 제13권3호
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• pp.190-199
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• 2008

북동태평양 열대 해양의 해수특성과 해양구조를 파악하기 위하여 2005년 7-8월에 $131.5^{\circ}W$ 관측선에서 관측한 CTD 자료를 분석하였다. 또한 적도 부근 태평양의 해수특성을 전반적으로 이해하기 위하여 서태평양 $137^{\circ}-142^{\circ}E$에서의 CTD 자료도 분석하여 동태평양의 분석 결과와 비교하였다. 여름철 동태평양의 표층수온은 적도반류 해역에서 가장 높았다. 이것은 $28^{\circ}C$ 이상의 고온수가 봄과 여름철에 적도반류를 타고 서태평양으로부터 동태평양으로 이동하여 약 $4^{\circ}-15^{\circ}N$ 사이에서 동서로 연결되기 때문이다. 북적도해류의 표층에 나타나는 저염분 고용존산소의 해수는 동태평양의 파나마만으로부터 서태평양의 필리핀 부근까지 이동하는 저염분수 때문이다. 반면 남적도해류의 표층에 고염분과 저용존산소의 해수가 분포하는 것은 남태평양 아열대 기원의 고염분수가 적도를 넘어 남적도해류 표층의 열대해수(Tropical Water)와 심층의 고염분수를 형성하고 있기 때문이다. 수심 약 500-1500 m 사이의 중층에서는 염분최소층이 분포하는데, $5^{\circ}N$ 이남은 남극중층수(AAIW) 기원의 해수가, $5^{\circ}N$ 이북은 북태평양중층수(NPIW) 기원의 해수가 분포한다. $4^{\circ}-6^{\circ}N$ 해역에서는 직경 약 200 km이며 반시계 방향으로 회전하는 냉수성 소용돌이(cold eddy)가 관측되었다. 서태평양에 비해 동태평양에서 표층수온은 $1^{\circ}C$ 이상 낮았으며 표층염분은 높았다. 적도 부근의 표층 아래에 분포하는 고염분수는 동태평양에서 상대적으로 저염분(약 0.5 psu) 이었고, $14^{\circ}N$ 이남에서 염분최소층의 염분과 밀도는 동태평양에서 높았다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.685-689
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• 2016

Opisthorchiasis is still a major health problem in rural communities of Thailand. Infection is associated with cholangiocarcinoma (CCA), which is found frequently in Thailand, particularly in the northeastern. Therefore, this study aimed to evaluate the effectiveness of health intervention in the population at risk for opisthorchiasis and CCA. A quasi-experimental study was conducted in Meuang Yang district, Nakhon Ratchasima province, northeastern Thailand, between June and October 2015. Participants were completed health intervention comprising 4 stations; 1, VDO clip of moving adult worm of liver fluke; 2, poster of life cycle of liver fluke; 3, microscopy with adult and egg liver fluke; and 4, brochure with the knowledge of liver fluke containing infection, signs, symptoms, related disease, diagnosis, treatment, prevention, and control. Pre-and-post-test questionnaires were utilized to collect data from all participants. Students paired t-tests were used to analyze differences between before and after participation in the health intervention. Knowledge (mean difference=-7.48, t=-51.241, 95% CI, -7.77, -7.19, p-value =0.001), attitude (mean difference=-9.07, t=-9.818, 95% CI=-10.9, -7.24, p-value=0.001), and practice (mean difference=-2.04, t=-2.688, 95% CI=-3.55, -0.53, p-value=0.008), changed between before and after time points with statistical significance. Community rules were concluded regarding: (1) cooked cyprinoid fish consumption; (2) stop under cooked cyprinoid fish by household cooker; (3) cooked food consumption; (4) hygienic defecation; (5) corrected knowledge campaign close to each household; (6) organizing a village food safety club; (7) and annual health check including stool examination featuring monitoring by village health volunteers and local public health officers. The results indicates that the present health intervention program was effective and easy to understand, with low cost and taking only a short time. Therefore, this program may useful for further work at community and provincial levels for liver fluke prevention and control.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2625-2628
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• 2012

Introduction: Fumonisin B1 (FB1) is a toxic and carcinogenic mycotoxin produced in cereals due to fungal infection. This study was conducted to determine FB1 contamination of rice and corn samples and its relationship with the rate of esophageal cancer (EC) in a high risk area in northeastern Iran. Methods: In total, 66 rice and 66 corn samples were collected from 22 geographical subdivisions of Golestan province of Iran. The levels of FB1 were measured for each subdivision by thin layer and high pressure liquid chromatographies. The mean level of FB1 and the proportions of FB1 contaminated samples were compared between low and high EC-risk areas of the province. Results: The mean of FB1 levels in corn and rice samples were 223.64 and 21.59 ${\mu}g/g$, respectively. FB1 contamination was found in 50% and 40.9% of corn and rice samples, respectively. FB1 level was significantly higher in rice samples obtained from high EC-risk area (43.8 ${\mu}g/g$) than those obtained from low risk area (8.93 ${\mu}g/g$) (p-value=0.01). The proportion of FB1 contaminated rice samples was also significantly greater in high (75%) than low (21.4%) EC-risk areas (p-value=0.02). Conclusion: We found high levels of FB1 contamination in corn and rice samples from Golestan province of Iran, with a significant positive relationship between FB1 contamination in rice and the risk of EC. Therefore, fumonisin contamination in commonly used staple foods, especially rice, may be considered as a potential risk factor for EC in this high risk region.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1433-1436
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• 2016

Background: Cholangiocarcinoma (CCA), a major problem of health in Thailand, particularly in Northeastern and Northern regions, is generally incurable and rapidly lethal because of presentation in stage 3 or 4. Early diagnosis of stage 1 and 2 could allow better survival. Therefore, this study aimed to provide a distribution map of populations at risk for CCA in BuaYai district of Nakhon Ratchasima province, Northeast Thailand. Materials and Methods: A cross-sectional survey was carried out in 10 sub-districts and 122 villages, during June and November 2015. The populations at risk for CCA were screened using the Korat CCA verbal screening test (KCVST) and then risk areas were displayed by using Google map (GM). Results: A total of 11,435 individuals from a 26,198 population completed the KCVST. The majority had a low score of risk for CCA (1-4 points; 93.3%). High scores with 6, 7 and 8 points accounted for 1.20%, 0.13% and 0.02%. The population at risk was found frequently in sub-district municipalities, followed by sub-district administrative organization and town municipalities, (F=396.220, P-value=0.000). Distribution mapping comprised 11 layers: 1, district; 2, local administrative organization; 3, hospital; 4, KCVST opisthorchiasis; 5, KCVST praziquantel used; 6, KCVST cholelithiasis; 7, KCVST raw fish consumption; 8, KCVST alcohol consumption; 9, KCVST pesticide used; 10, KCVST relative family with CCA; and 11, KCVST naive northeastern people. Geovisual display is now available online. Conclusions: This study indicated that the population at high risk of CCA in Bua Yai district is low, therefore setting a zero model project is possible. Key success factors for disease prevention and control need further study. GM production is suitable for further CCA surveillance and monitoring of the population with a high risk score in this area.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1293-1297
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• 2016

Cholangiocarcinoma (CCA) is a serious problem in Thailand, particularly in the northeastern and northern regions. Database of population at risk are need required for monitoring, surveillance, home health care, and home visit. Therefore, this study aimed to develop a geographic information system (GIS) database and Google map of the population at risk of CCA in Mueang Yang district, Nakhon Ratchasima province, northeastern Thailand during June to October 2015. Populations at risk were screened using the Korat CCA verbal screening test (KCVST). Software included Microsoft Excel, ArcGIS, and Google Maps. The secondary data included the point of villages, sub-district boundaries, district boundaries, point of hospital in Mueang Yang district, used for created the spatial databese. The populations at risk for CCA and opisthorchiasis were used to create an arttribute database. Data were tranfered to WGS84 UTM ZONE 48. After the conversion, all of the data were imported into Google Earth using online web pages www.earthpoint.us. Some 222 from a 4,800 population at risk for CCA constituted a high risk group. Geo-visual display available at following www.google.com/maps/d/u/0/edit?mid=zPxtcHv_iDLo.kvPpxl5mAs90&hl=th. Geo-visual display 5 layers including: layer 1, village location and number of the population at risk for CCA; layer 2, sub-district health promotion hospital in Mueang Yang district and number of opisthorchiasis; layer 3, sub-district district and the number of population at risk for CCA; layer 4, district hospital and the number of population at risk for CCA and number of opisthorchiasis; and layer 5, district and the number of population at risk for CCA and number of opisthorchiasis. This GIS database and Google map production process is suitable for further monitoring, surveillance, and home health care for CCA sufferers.

• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.231-234
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• 2016

Opisthorchis viverrini infection is associated with cholangiocarcinoma particularly in the cases of chronic or re-infection. This presents a serious health problem in northeastern and northern Thailand. A community base approach is required for surveillance. Therefore, in a pilot project, re-examination of O. viverrini infection was conducted in the 3 districts of Nakhon Ratchasima province, Thailand, during June and October 2015. A total of 355 participants from a 194,152 population, was selected through multi-stage sampling. O. viverrini infection was determined using modified Kato Katz thick smear technique. Participants were 229 males and 126 females, and aged ${\geq}30$ years old. Prevalence of O. viverrini infection was 2.25% (8/355 participants). O. viverrini infection was slightly higher in females (3.17%), and age group between 41-50 years (4.49%). Mueang Yang district had a highest of O. viverrini infection rate (2.82%), and followed by Bua Yai (2.48%), and Chum Phuang (1.84%), respectively. O. viverrini infection rate was increased from year 2012 to 2015 particularly in Bua Yai and Mueang Yang. These re-examinion results indicate that opisthorchiasis is still problem in community of Nakhon Ratchasima province, therefore, the provincial-wide scale is need required. Furthermore health education is need intervened in the infected group, and screening of cholangiocarcinoma is urgently concerned.