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Showing papers by "Kyungpook National University published in 1980"


Journal ArticleDOI
01 Jan 1980
TL;DR: In this article, the mode and amount of the crustal movements are discussed based on the relative sea-level curve reconstructed from topographical and chronological data including 36 14 C dates.
Abstract: Prominent Holocene marine terraces classified into four levels in southern Boss, have recorded the history of seismic crustal deformation by large earthquakes along the Sagami trough. The mode and amount of the crustal movements are discussed based on the relative sea-level curve reconstructed from topographical and chronological data including 36 14 C dates. 1. The relative sea-level curve indicates four times sudden sea-level drops at 6, 150 y. B. P., 4, 350 y. B. P., 2, 850y. B. P. and 250y. B. P., caused by seismic upheavals associated with -earthquakes like that of Genroku Taisho type (Fig. 5). 2. The duration of interseismic period relates to the amount of upheaval associated with the preceding earthquake which measures 5.5m, 5m, 7m and 5.5m respectively. 3. Using the method of least squares, long-term mean uplift rate is calculated 3.0mm/year based on the relative altitude of sea-level (H) and the period (T) just before each earthquake (Fig. 7). 4. Trend of sea-level change deduced from difference between the long-term mean uplift rate and the uplift rate calculated by each earthquake, exhibits general regression toward 2, 700y. B. P. and transgression thereafter. 5. The same kind of seismic crustal movement and trend of sea-level change are also revealed from the data of Holocene emerged coral reefs in Kikaijima, the Ryukyu Islands (Figs. 6 and 7).

44 citations


Journal ArticleDOI
01 May 1980
TL;DR: In this article, the sea level changes on the east coast of Korea Peninsula are discussed based on sedimentary facies of alluvium and their radiocarbon ages, and minor fluctuations of the sea-level are restored by grain size analysis of the alluvial deposits from 10, 000y. B. P.
Abstract: Holocene sea-level changes on the east coast of Korea Peninsula are discussed based on sedimentary facies of alluvium and their radiocarbon ages. Minor fluctuations of the sea-level are restored by grain size analysis of alluvial deposits from 10, 000y. B. P., and by pollen analysis of peaty deposits since 6, 000y. B. P.. Main results are as follows ; 1. Sea-level was about -25m a. s. 1, around 10, 000y. B. P. and it rose to about -10m a. s. 1, around 7, 000y. B. P.. The sea nearly attained to its present level around 6000y. B. P., and has approximately stood at the same level with minor fluctuations since then. 2. As the sea-level curve obtained from the study area resembles to those from many other parts of the world in its altitudes and ages, the existance of active crustal movements during Holocene are discarded on the east coast of the Peninsula. 3. Gravel bed was deposited about -20m a. s. 1. in Pohang plain at the time of temporary stable sea-level recorded between 10, 000y. B. P. and 9, 000y. B. P. during the period of rapid transgression. 4. During the period of stable sea-level since 6, 000y. B. P., beach ridges have been formed at the time of three comparatively high levels.

22 citations


Journal ArticleDOI
TL;DR: The results obtained in the present study indicate that endemic foci of Clonorchis sinensis exist in the river Taewha and the prevalence of the liver fluke among the residents is still high.
Abstract: In order to determine the epidemiological patten of the liver fluke, Clonorchis sinensis, the locality where the snail, Parafossarulus manchouricus, is abundant, the infestation rates for the cercarial and metacercarial larvae of digenetic trematodes in the snail and fish hosts, and the prevalence of Clonorchis sinensis among the residents in the vicinity of river Taewha, Kyungnam Province, Korea were studied from March 1979 to September 1980. Four snail habitats were found in the river Taewha. The population density of the snail per square meter of the habits ranged from 10 to 500, with an average of 150. Among the 4 snail habitats, three, Baek-cheon, Sa-yeon and Taewha had snails infected with the cercaria of Clonorchis sinensis, and the proportion of infested snails in the three habitats was very low, the average being 0.59 per thousand. Four species of fresh-water fish, the bullhead, Coreobagrus brevicorpus, the Korean shiner, Gnathopogon atromaculatus, the flat bitterling, Paracheilognathus rhombea, and the striped shiner, Pungtungia herzi among ten species of fish examined harbored the metacercaria of Clonorchis sinensis. The intensity of infestation with the cyst of Clonorchis sinensis in the four species of fish was low. The approximate number of the cysts per gram of flesh was between 3.5 in Paracheilognathus rhombea and 21.5 in Gnathopogon atromaculatus. Seven kinds of laval tremathodes, Clonorchis sinensis, Cyathocotyle orientalis, Echinochasmus species, Exorchis oviformis, Metacercaria hasegawai, Metagonimus yokogawai and Metorchis orientalis were found from ten species of fish examined. In general, the infestation rates for the encysted larvae of digenetic trematodes varied from fish to fish. The infection rate for Clonorchis sinensis among the residents in the vicinity of river Taewha was relatively high, 22.2 % by the formalin-ether sedimentation technique, and the difference in the rate of infection between males and females found to be siginificant(t > 2). Of these, the rate was 12.4 per cent in 483 elementary school children and 17.7 % in 761 middle and high school students. The results obtained in the present study indicate that endemic foci of Clonorchis sinensis exist in the river Taewha and the prevalence of the liver fluke among the residents is still high.

21 citations


Journal ArticleDOI
TL;DR: The population density of snails in the habitat and the infection of the snail with the cercariae of digenetic trematodes has decreased over the five-year period from 1975 to 1979, except for Loxogenes liberum.
Abstract: Studies were conducted to determine the ecology of the snail, Parafossarulus manchouricus, the seasonal variation of the snail population, and the infestation rates of these snails with the cercariae of digenetic trematodes, in the snail habitat of river Kumho, in Dongchon of Taegu city, in Kyungpook Province, Korea, from 1975 to 1979. The earliest time the snails were found was early in April every year. At that time the water temperature ranged from 13 to 14 degrees C. The population density of snails ranged from 2 to 8 per square meter. The highest population density of snails was encountered in late June and the water temperature was between 24 and 26 degrees C. The snails disappeared in early and mid-November, when the water temperature dropped to 10~13 degrees C. The average snail population in June was 115.9 per square meter in 1975 but in 1976 dropped abruptly to 30.5 and remained at approximately the same level in 1977. It then decreased at considerably lower rates, with the average of 18.7 in 1978 and 14.5 in 1979. The snails collected in the habitat were examined for the presence of cercariae of digenetic trematodes. Of these, four species, Clonorchis sinensis, Cyathocotyle orientalis, Exorchis oviformis, and Loxogenes liberum were found. The most frequently liberated cercaria was L. liberum 43.3 per cent, followed by E. oviformis 6.2 per cent and C. orientalis 1.5 per cent. The least frequently liberated was C. sinensis 0.1 per cent. In the monthly liberation rates for larval trematodes, the higher rates were observed in June, July and August every year, and the cercarial rates for Clonorchis sinensis, Cyathocotyle orientails and Exorchis oviformis demonstrate a fairly consistently fluctuating downward trend over the five-year period, except for Loxogenes liberum. Summarizing the results, this study indicated that the population density of snails in the habitat and the infection of the snail with the cercariae of digenetic trematodes has decreased over the five-year period from 1975 to 1979.

16 citations


Journal ArticleDOI
TL;DR: It is found that Sam-chun village, one of the three localitied in Wiseong county, where Ichinomiya (1924) surveyed, was still the endemic focus of Paragonimus westermani.
Abstract: This survey was undertaken to determine the recent prevalence of lung fluke, Paragonimus westermani, in the three localities of Wiseong county, Kyungpook Province, Korea and to compare the prevalence among the residents in the same areas between 1924 and 1980. The three localities, Ku-seong, Sam-chun, and Um-ji villages (dong) have been known as the endemic areas of Paragonimus westermani. The surveys were made on the general population. They were examined using intradermal test with Paragonimus westermani antigen, and the diagnosis of paragonimiasis was made depending on the positive intradermal reaction. The sputum examination could not be performed beacause the residents were inaccessible. The prevalence of Paragonimus westermani among the residents in the three communities varied from 1.4 % to 7.9 per cent, with an average of 4.0 per cent. Whereas, the average reported by Ichinomiya in 1924 was 4.7 %. There are no significant differences in the sex and age specific rates of infection between 1924 and 1980. With the abundant density of Semisulcospira snails and crayfish in Sam-chun stream and the high rate of infection with Paragonimus westermani among the residents in the village, it is found that Sam-chun village, one of the three localitied in Wiseong county, where Ichinomiya (1924) surveyed, was still the endemic focus of Paragonimus westermani.

6 citations


Journal ArticleDOI
TL;DR: It was found that Trichomonas vaginalis in Korean military personnel is one of the important diseases with a high indicence, and that the eradication of this disease is possible with extensive public health education and the administration of specific therapeutic agents to patients with trichomoniasis.
Abstract: A study of Trichomonas vaginalis in Korean military personnel, based on the discovery of motile trophozoites by prostate culture and urine wet smear methods, has been carried out during the period from May, 1975 to October, 1977. In the Army General Hospital clinics, specimens of prostatec secretion and urine were provided by the in- and out-patients without any noticeable genito-urinary symptoms. In a total of 977 specimens 33 cases were revealed positive for Trichomonas vaginalis. Of these, 23 cases were positive in both prostate culture and urine wet smear methods, 8 positive in the culture but negative in the wet smear, and 2 positive only in the wet smear. In comparing the demonstration rates for trichomonads by culture with those by smears, the former was more likely to give a positive result than the latter. The pattern of the incidence rate by age group was appreciably varied; 2.1 per cent in the 20-24 age group and 5.1 per cent from 25 to 29 and subsequently increased and reached a maximum of 5.7 per cent in the 40 and over age group. It was found that Trichomonas vaginalis in Korean military personnel is one of the important diseases with a high indicence, and that the eradication of this disease is possible with extensive public health education and the administration of specific therapeutic agents to patients with trichomoniasis.

5 citations



Journal ArticleDOI
TL;DR: The virus was tentatively named perilla mottle virus, which produced chlorotic local lesions on Chenopodium amaranticolor, C. quinoa, Gomphrena globosa, and Vicia faba while it produced systemic mottling on Perilla frutescens var.
Abstract: Mosaic plants of perilla were collected in Tokyo and Saitama prefecture. Virus particles detected in the diseased leaves were flexuous rods, about 13×760nm, with a helical symmetry of 3.4nm pitch. In ultrathin sections of the diseased leaves, the virus particles and cytoplasmic inclusions such as pinwheels and bundles were observed in the cytoplasm of virus-infected cells. By sap inoculation, the virus produced chlorotic local lesions on Chenopodium amaranticolor, C. quinoa, Gomphrena globosa, and Vicia faba, while it produced systemic mottling on Perilla frutescens var. acuta. The virus was also transmitted in a non-persistent manner by Myzus persicae (Sulz.). The virus was tentatively named perilla mottle virus.

1 citations


Journal ArticleDOI
TL;DR: It was found that there were no significant differences in the age and sex rates of demonstration between urban and rural children but there was a predominance of the small race of Entamoeba histolytica over the large race.
Abstract: School children between 6 to 12 years of age were studied for the presence of Entamoeba histolytica cysts in a period of 6 months, form March to August 1980. Fecal specimens collected form urban and rural children were examined first by the Lugol stained technique and then by the Faust's iron alum hematoxylin method. A total of 731 specimens were examined. Of these 26.9 per cent, 197 specimens, harbored the cysts. The demonstration rate for the cysts by age group varied from 19.6 to 43.5 per cent. The demonstration rate in boys was 24.4 per cent and in girls 29.8 per cent. Similarily, the rate in urban and rural area was 32.4 and 24.1 per cent, respectively. It was found in the present study that there were no significant differences in the age and sex rates of demonstration between urban and rural children but there was a predominance of the small race of Entamoeba histolytica over the large race.