• Animal cells and systems
• /
• 제2권1호
• /
• pp.107-111
• /
• 1998

Two kinds of humoral factors were observed in 2 orders, 7 families, 10 genera, and 15 different species of Korean ascidians. They are the naturally occuring hemagglutinins and/or hemolysins against human erythrocytes A, B, and 0. All but two species showed aggregative activity, although there were considerable variations in titer. The weak agglutinating and lytic activities were increased in the presence of $Ca^{++}$. Much higher activities of agglutination and/or lysis were shown in the hemolymph than extracts from tissues, and a higher response was shown in adults than in juveniles. No distinct differences from collected locations were observed. The hemolymph of Ciona intestinalis showed a strong hemolytic (cytotoxic) and weak agglutinins capacities. In addition, hemolymph of Styela plicata and Styela clava clava also showed hemoagglutining and hemolytic activities. Botryllus tuberatus had hemagglutining and weak lytic activities. Other species showed only hemagglutining activity. These agglutining activities are probably responsible for carbohydrate recognition in solitary or colonial ascidian. The lytic activity is probably responsible for antibacterial defense and nonfusion reactions between allogeneic colonial ascidians, especially the genus of Botryllus. The occurrences of humoral factors in ascidians were independent of their geographic distributions.

• Animal cells and systems
• /
• 제14권1호
• /
• pp.31-36
• /
• 2010

The pinewood nematode Bursaphelenchus xylophilus causes pine wilt disease and is a serious economic concern for the forest industry of South Korea. To achieve effective control with limited resources, it is necessary to clarify the transmission routes and mechanisms of dispersal of this organism. Highly polymorphic and easy-to-use molecular markers can be used for investigating this aspect. In this study, we evaluated the usefulness of amplified fragment length polymorphisms (AFLPs) for investigating the genetic variations of B. xylophilus and related individuals from China, Japan, and South Korea. The AFLP patterns obtained in our study were similar to the microsatellite patterns reported in a previous study; our AFLP patterns indicated high genetic variability and cryptic genetic structure, but did not indicate any peculiar geographic structure. Moreover, the genetic distances between individuals suggested that the Korean population was affected to a greater extent by the Chinese population than the Japanese population. Further, the gene flow among the related species appeared to be limited; however, there may be also the possibility of genetic introgression among species. These results confirm the usefulness of AFLPs for understanding the epidemiology of pine wilt disease, thereby contributing to the effective control of this disease.

• 대기
• /
• 제21권4호
• /
• pp.361-371
• /
• 2011

In this study, characteristics and trends of tropical night (TN) are investigated by using the KMA 14 observation data for the recent 50 years (1958-2007) over South Korea. The TN is defined as a day with a daily minimum temperature exceeds the absolute threshold temperature ($25^{\circ}C$), and the relative deviation from normal temperature, 95th percentile of all observed daily minimum temperature. Although the spatial distribution of TN occurrence depends on the choice of the definitions, the frequency of TN shows strong spatial and interannual variations with the minimum at high land area (Chupungnyeong and wet years) and maximum at southern coastal area and large city area (Jeju, Busan, Seoul, Daegu). Most of TN occurs in August (56%) and July (41%), and the duration date of TN is proportional to the frequency of TN without regard to the definition method. In general, increasing trends are found in the TN time series without regard to the analysis method, but the trends are clearly depending on the analysis period and geographic locations. Decreasing trends are prominent during the most of analysis period, especially until the mid of 1990, whereas strong increasing trends are found during recent 30 years (1988-2007), especially at Jeju, Ulsan, Daegu and Pohang. Also the severity of TN is significantly increased in recent years.

• Environmental Engineering Research
• /
• 제22권4호
• /
• pp.369-376
• /
• 2017

The trend analysis of the study was acquired by selecting multiyear monthly groundwater table data and monitors the wells in each sub-district under the study area. The intention of this research was to analyze the outcome of the non-parametric Mann-Kendall test at greater than the significance level which is 95% of groundwater level in Sylhet. The aptitude is effective at two conjunctures where the confidence bounds are 95% and it meets the estimate line of Sen's. To calculate and assess the spatial differences in the inanition of groundwater table, geostatistical methods was applied based on data from 27 groundwater wells during the period from January 1975 to December 2011 which were obtained from a secondary source, Bangladesh Water Development Board. The geographic information system was used to assess the spatial change in order to find the level of groundwater. Cross-validation errors were found within an advisable level in estimating the groundwater depth with different interpolation models of ordinary kriging methods. Finally, surface maps were generated with the best-fitted model. The southeast region was found highly vulnerable from groundwater level point of view. Northern region was detected highest hazard prone area for diverge groundwater using kriging method.

• 한국산학기술학회논문지
• /
• 제12권1호
• /
• pp.507-512
• /
• 2011

최근 하천의 유동 및 하상 자료를 광범위한 영역에서 신속하게 계측할 수 있는 전자기파 기반의 수리계측기기들이 등장하여 하천의 특성을 이해하는 방식을 전통적인 수치모델링을 통한 방식으로부터 자료만을 활용하는 방식으로 전환되고 있다. 본 논문은 최신 관측기기로 초음파유속계(ADCP), 이미지 유속계(LSPIV), 복수빔 음파수심계(MBES), 공중 전파수심계(ABL) 의 관측 방식과 적용 사례를 보여준다. 그리고 관측된 2차원 혹은 3차원의 유동 및 하상 자료를 GIS에 기반하여 상호 연계하고 저장하여 하천의 시공간적인 변화를 추적할 수 있게 하는 하천정보화시스템의 구축방안을 제시한다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권1호
• /
• pp.27-30
• /
• 2013

Background: Salivary gland tumors (SGT) are one of the most complex human neoplasms, demonstrating variations in their clinicopathological profile related to racial and geographic differences. Few studies with large samples have been reported in Iran. We here investigated a large group of patients in southern Iran. Materials and Methods: In this retrospective study, all cases of primary epithelial salivary gland tumors, which had been recorded in a 5 years period from 2005-2009, were enrolled. Clinical data such as histopathologic type and site of the lesion as well as patients' age and gender were analyzed. Results: Data of 366 cases of SGTs were recorded. Pleomorphic adenoma (80.2%) and adenoid cystic carcinoma (46.6%) were the most common benign and malignant neoplasms. Male to female ratio (M/F) and the mean age of patients were 1:1.05 and 37.7 for benign tumors while they were 1.2:1 and 50.6 for malignant tumors, respectively. Parotid and minor salivary glands were involved more frequently. Conclusions: Although the salivary gland tumours encountered were similar in most of their characteristics to those reported in other countries, some differences such as relative frequency and age and gender prevalence were discovered. These findings should help surgeons and pathologists for more accurate diagnosis, management and treatment.

• The Korean Journal of Ecology
• /
• 제18권3호
• /
• pp.353-366
• /
• 1995

To study the relationship between the germination response and geographical distribution, the seeds of Rumex acetocella were collected from nine sites (Taegwallyong, Alps lodge, Kans'ong, Sokch'o, Chumunjin, Suwon, Taechon, Sukgok, Mokpo) of different latitudes and altitudes. The populations of Rumex acetocella were subdivided into four groups based on the characteristics of the seed germination. The first group of Rumex acetocella (Taegwallyong, Alps lodge) germinated rapidly in early spring, the second group (Suwon, Teachon) in late summer through early autumn, and the third group(Sukgok, Mokpo) slowly in late autuman with various conditions. The thermal time values needed for the germination rate of 10% to 60% for these three groups indicated that the germination rate was low at the lower latitude, while it was increased as the latitude elevated. The population of the fouth group (Kansong, Sokcho, Chumunjin) showed the narrow optimum temperature range of germination response and the highest thermal time value to germinate 10% to 30% of seeds. The seeds in the high latitude region with relatively mild winter germinated synchronously in early autumn. These different germination responses of Rumex acetocella to geographic variations were thought to be an ecological strategy to survive in different environmental conditions.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권7호
• /
• pp.3469-3476
• /
• 2016

Background: The cancer research literature suggests that women, especially premenopausal women, have lower cancer mortality rates than men. However, it is unclear if that is true for populations at all age levels in all countries and what factors affect such sex differences. This paper attempts to fill that gap. Materials and Methods: Sex- and country-specific cancer mortality data were statistically analyzed with particular attention to geographic, social, and economic factors that may affect the sex differences. Results: The sex differences were age and country specific, rather than universal. Premenopausal women actually tend to have a disadvantage compared to men or postmenopausal women. Male cancer mortality appears to be the affecting factor in explaining variations in sex differences. Latitude of residence and literacy rate are the affecting factors in cancer mortality and sex differences. African and Latin American countries tend to have a female disadvantage, while East Asian and Eastern European countries are more likely to have a female advantage. Conclusions: The findings challenge the cancer mortality literature and indicate that the sex differences and their possible causes are more complicated than the current literature suggests. They also highlight the urgency of adapting age- and country- specific health systems and policies to better meet the needs of younger women.

• 농촌계획
• /
• 제10권1호
• /
• pp.19-26
• /
• 2004

In this paper, forestry area change effect on the soil erosion in Asan lake watershed was estimated. Temporal variations of land use in the study watershed were analyzed from Landsat-5 TM remote sensing images. Geographic Information System (GIS) combined with Universal Soil Loss Equation (USLE) was used to estimate the soil erosion of Asan lake watershed. Spatial data for each USLE factors was obtained from the Landsat-5 TM remote sensing images and 1/25,000 scale digital contour maps. Sediment yield to Asan lake was estimated by sediment delivery ratio and sediment accumulation in lake was estimated by trap efficiency. The estimation methods were validated for sediment accumulation in Asan lake. From the hydrographic survey from 1974 to 2003 for Asan lake, sediment accumulation was measured. The estimated accumulation sediment of 303,569ton/yr showed similar value with observed of 295,888ton/yr. From the validated estimation methods, the increasing amount of soil erosion when 1% of forest area in Asan lake watershed decreases was calculated from 12.91 to 1482.05ton/yr.

• 한국수자원학회논문집
• /
• 제31권1호
• /
• pp.27-34
• /
• 1998

우물수원의 보호구역의 범위를 결정하기 위해서 GIS를 이용한 지하수 모의모형ㅇ과 Arc/Info의 Grid 함수를 이용하였다. GIS를 이용한 지하수 모형은 Arcview GIS를 사용하여 모형의 시간변화를 고려하고 자료의 입력 및 조작, 모의, 결과의 표시 등을 GIS내에 통합한 모형으로 개발하였다. 모형을 적용하기 위해 미국환경의 자료를 사용하였으며 적용시킨 결과 지하수 모형에서 계산된 수두 분포와 우물의 영향권을 계산한 값이 본 논문에서 계산한 값과 거의 비슷한 값을 나타내어 모형의 타당성을 검증하였다. 본 모형은 GIS내에서 모든 처리가 이루어지므로 우물수원의 보호구역의 범위를 설정하는데 효율적인 방법이 될수 있을 것이다.