• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1994.07a
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• pp.184-215
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• 1994

The Hydrogeologic data of 455 water wells comprising geologic and aquifer test were analyzed to determine hydrogeoloic characteristics of Cheju island. The groundwater of Cheju island is occurred in unconsolidated pyroclastic deposits interbedded in highly jointed basaltic and andesic rocks as high level, basal and parabasal types order unconfined condition. The average transmissivity and specific yield of the aquifer are at about 29,300m$^2$/day and 0.12 respectively. The total storage of groundwater is estimated about 44 billion cubic meters(m$^3$). Average annual precipitation is about 3390 million m$^3$ among which average recharge amount is estimated 1494 million m$^3$ equivalent 44.1% of annual precipitation with 638 million m$^3$ of runoff and 1256 million m$^3$ of evapotranspiration. Based on groundwater budget analysis, the sustainable yield is about 620 million m$^3$(41% of annual recharge)and rest of it is discharging into the sea. The geologic logs of recently drilled thermal water wens indicate that very low-permeable marine sediments(Sehwa-ri formation) composed of loosely cemented sandy sat derived from mainly volcanic ashes, at the 1st stage volcanic activity of the area was situated at the 120$\pm$68m below sea level. And also the other low-permeable sedimentary rock called Segipo-formation which is deemed younger than former marine sediment is occured at the area covering north-west and western part of Cheju at the $\pm$70m below sea level. If these impermeable beds are distributed as a basal formation of fresh water zone of Cheju, most of groundwater in Cheju will be para-basal type. These formations will be one of the most important hydrogeologic boundary and groundwater occurences in the area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.1
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• pp.13-26
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• 2001

Six ferromanganese crusts from the Lomilik and Litatfooki seamounts in the Marshall Islands were analyzed for texture, geochemistry and stratigraphy to delineate the paleoceanographic conditions. The crusts can be divided into three layers; 1) outermost massive layer (Layer 1), 2) middle porous Fe-oxides rich layer infllled with biointemal clasts (Layer 2), and 3) innermost massive layer cemented and/or replaced by carbonate fluoapatite (CFA) (Layer 3). The Layer 1 contains higher Mn, Co, Ni, and Mg than other two layers, and the Layer 2 was relatively more enriched in Fe, Al, Ti, Ba, Cu, and Zn. However, the Layer 3 shows higher Ca and P and lower Mn, Fe, Co, and Ni contents than overlying two layers. Based on the Co-chronometry, the crusts are postulated to have begun to grow from 56-31 Ma (early Eocene to Oligocene). The boundaries between layers 1 and 2, and layers 2 and 3 are dated to be 7-3 Ma and 26-14 Ma, respectively. High contents of Ca and P in Layer 3 clearly indicate that the layer had been phosphatized prior to the formation of Layer 2. Considering the well-preserved mjcrostructures in Layer 3, it is unlike that the crusts themselves were recrystallized in suboxic condition. Also, the lower Co concentrations in Layer 3 may imply that the Co supply was not constant during the formation of Layer 3. Layer 2, characterized by the porous texture, grew over Layer 3 during 26-9 Ma. Internal biogenic sediments including foraminifera within the original cavities and the enrichment of organophillic elements such as Ba, Cu, and Zn, suggest that Layer 2 have below high production regions. Also, high content of allumino silicate components may indicate increased terrigeneous input during the formation of Layer 2. The Layer 2. The Layer 1 has been subjected to little diagenetic influence since the Pliocene.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.279-288
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• 2011

To suggest the weed management technique for environment friendly rice cultivation, we investigated occurrence patterns of weeds, the actual condition of weed management, and rice yield at the environment friendly agricultural complex located in Honam and Chungnam regions. The practical performance of weed management was relatively satisfactory in decreasing order of agricultural technique with golden-apple-snail (GAS) > agricultural technique with duck (Duck) > agricultural technique with rice bran (RB) > agricultural technique with soft-shelled turtle (ST). In the rice fields employed by agricultural technique with GAS, the dominant weeds were Echinochloa crus-galli, Ludwigia prostrata, Monochoria vaginalis, Sagittaria trifolia, and Aneilema keisak. However, E. crus-galli, M. vaginalis, L. prostrata, Aeschynomene indica and Bidens frondosa were found as dominant weeds at the fields using the Duck and E. crus-galli, M. vaginalis, L. prostrata, Polyganum hydropiper and Eleocharis kuroguwai at the fields using RB. In comparison of rice yield ($5.2\;MT\;ha^{-1}$) obtained from the conventional cultivation using herbicides, about 93% was reached by Duck, about 91% by GAS, about 92% by RB, and about 78% by ST. When rice qualities obtained from environment friendly rice cultivation were compared with those from the conventional cultivation, the producing rates of perfect kernel, immature kernel, immature opaque kernel, cracked rice, and damaged kernel were lower in the former cultivation, whereas contents of protein, amylose, and fatty acid were similar in the two cultivation methods. The problems found in the environment friendly agriculture were poor plowing and harrowing, carless irrigation management, and geological poor condition as cultivation area with cold water. These have caused severe infestation of weeds, frequent incident of disease and insect pest, and rice lodging. This resulted in reduction of rice yield as high as about 32 to 79% as compared with the conventional cultivation using herbicides.

• Parasites, Hosts and Diseases
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• v.27 no.3
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• pp.177-186
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• 1989

Observations were made on the differences in cell-mediated immune responses in the mice infected with strongly pathogenic Naegleria fewleyi ITMAP 359, weakly pathogenic Naegzeria jadini 0400, or non.pathogenic Naegleria gruberi EGB, respectively. Variations in cell-mediated responses and changes in antibody titers according to the duration after infection wore noted. Infections were done by dropping $5{\;}{\mu}l$ saline suspension containing $10{\times}10^4$ trophozoites cultured Bxenically in the CGVS medium into the right nasal cavity of ICR mice aging about 6~7 weeks, under the anesthesia by intraperitoneal injection of'secobarbital. Following infection, delayed type hypersensitivity(DTH) iesponses in the footpad and blastogenic responses of the mouse spleen cells using [$^3H$]-thymidine were observed on the day 1, 4, 7, 10 and 14 after infection. For the preparation of amoeba Iysates, each of cultured trophosoites were homogenized with an ultrasonicator, and centrifugated at 20,000 g. The supernatants of amoeba Iysates were used as the mitogen'and antigen for ELISA. Confanavalin A(Con. A) and lipopolysaccharide(LPS) were also used as mitogens in the blastogenic response. 1. The mice infected with N, fowleri showed the mortality rate of 75.7%. The rate was 6.2% for the N. jadini infected group, while no dead mouse was observed for N. gruberi infections. 2. In regard to DTH responses in the H. fewleri infected mice, the level increased in com- parison to the control group but declined after 7 days. An increase was also noted for the JV. jadini group after 1 day, but gradual decreases were observed through the infection period. In addition, no difference was noted between the N. gruberi infected and control groups. 3. Concerning the blastogenic response of the splenocytes, it increased after 10 days in the experimental group of N, fcwleri infection, but the differences ware not statistically significant compared with control group. It was evident that N. jadini group was not different from control group either, while there was a tendency of decrease in SV. gruberi infected group. In regard to the blastogenic response of the splenocytes by LPS, it was found that the N. fowlgri, N. jadini and N. gruberi infected groups had no differences from the control group. 4. The serum antibody titer of N. fcwleri and N. jadini infected mice increased from the day 7 and 14 after infection respectively, while the N. gruberi infected mice showed no increase. In summary of the results, it was observed that there were differences in the cell-mediated immune responses and serum antibody titers in the mice infected with strongly pathogenic JV. fowleri, weakly pathogenic N. jadini, or non.pathogenic N. gruberi, respectively.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.23-34
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• 1989

In an attempt to investigate the effect of Hymenolepis dana infection on immunological responses to sRBC in ICR strain of mice, cellular and humoral immune responses were chronologically monitored after sensitization with sRBC. Mice weighing about 20 g were allocated into artificial and natural infection groups. The shell-free eggs of H. dana were inoculated into mice on the day 0 (initial) and day 10 in the former group, and praziquantel (25 mg/kg/day) was administered for 3 days to the one half of the mice at the 15th day after the first inoculation and to all of the mice in natural infection group. In artificial infection group, the delayed-type hypersensitivity (DTH) to sRBC was considerably decreased on the day 10 after the first inoculation, and then elevated gradually to normal. Eosinophils in the peripheral blood increased slightly. The hemagglutinin (HA) and hemolysin (HE) titers during the early stage were shown to be more or less higher than those of control. Thereafter, the titers were returned to normal, followed by a transient decrease on the day 15 post-infection. The sRBC rosette and antibody-treated rosette-forming capacities on the day 15 post.infection were temporarily lowered but became higher thereafter. The mucosal mast cells (MMC) in the small intestine were gradually increased to make a peak on the day 10 post-infection and then maintained more or less at lower level. After praziquantel treatment, the DTH and the number of eosinophils were decreased slightly and the MMC number and sRBC rosette-forming capacity were considerably decreased. The titers of HA and HE and antibody-treated rosette-forming capacity, however, were elevated in general. In natural infection group, the DTH, the number of eosinophils, and MMC which were elevated due to H. dana infection were gradually returned to normal after prasiquantel treatment. The titers of HA and HE which were decreased by parasite infection were increased to normal after the treatment. However, the capacities of sRBC rosette or antibody-treated rosette formation were maintained at low levels in spite of the treatment. These results revealed that the immune responses to sRBC were significantly activated during H. dana infection, although they were transiently decreased during the days 10~15 post-infection.

• Parasites, Hosts and Diseases
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• v.33 no.1
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• pp.45-54
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• 1995

Two-day-old chickens{\;}and{\;}mallards were orally inoculated with one of % doses varying from $2{\;}{\times}{\;}10^2{\;}to{\;}2{\;}{\times}{\;}10^6$ of C. bailevi oocysts per individual. Generally, the more oocysts Inoculated were, the longer the patent periods were, and the more oocysts shedding were. Meanwhile increasing the inoculative dose, the prepatent periods were shortened except that mallards inoculated with $2{\;}{\times}{\;}10^2and{\;}2{\;}{\times}{\;}10^3$ oocysts foiled to produce the oocysts. The more parasites involving oocysts appeared from the chicken in comparison to the mallard. In the chickens challenged with a single dose of $2{\;}{\times}{\;}10^6$ oocysts, a small number of oocysts were detected from feces on days 4-14 after challenge infection (ACI) in all of carrageenan administered groups and in the control groups inoculated with $2{\;}{\times}{\;}10^2{\;}and{\;}2{\;}{\times}{\;}10^3$ oocysts. In the mallards, a few oocysts were also recognized on days 5-15 ACI in all of carrageenan treated groups and in the control groups inoculated with $2{\;}{\times}{\;}10^2,{\;}2{\;}{\times}{\;}10^3{\;}and{\;}2{\;}{\times}{\;}10^4$ oocysts. Just prior to challenge infection, phagocytic activity of peritoneal macrophages (Me) and the number of peripheral Mc in both birds were significantly decreased in the carrageenan treated groups as compared to the control groups. Mild challenge inection in both birds denoted that the immunogenicity of C. bailelli to the birds was very strong, despite MB blocker carrageenan administration.

• Korean Journal of Veterinary Research
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• v.20 no.2
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• pp.179-197
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• 1980

A survey was made from March 1978 through Feb. 1979 to know infection rate of parasites and incidence of diseases in 1968 cattle of 240 rearing and fattening cattle herds (1746 Korean native cattle, 186 Holstein, 34 Charolais and 2 Hereford) raising in 28 cities and counties of Gyeongbug district. The results obtained are summarized as follows: 1. The rate of nematoda infection was about 49.0% in the examined cattle. These nematodes were identified as Mecistocirrus sp., Oesophagostomum sp., Bunostomum sp., Trichostrongylus spp., Strongyloides sp. and other 3 species. Infection rate of nematoda in fattening and breeding cattle was higher than that in rearing calves, 44.3% of the positive cattle were infected with 2 to 5 species, and incidence of mixed infection was high in fattening cattle. 2. The rate of coccidal infection was 10.9%. Eimeria $z{\ddot{u}}rni$, Eimeria bovis and Eimeria bukidnonensis were mainly found in the examined cattle. The infection rates of cocidia in Holstein, breeding Korean cows, rearing Korean calves and fattening Korean cattle were 27.3%, 15.8%, 11.2% and 9.1%, respectively. 3. The rate of trematoda was 14.6% with Fasciola spp. (11.2%), Eurytrema spp. (2.0%), and Paramphistomum spp. infections (1.4%). Breeding Korean cows, fattening Korean cattle, Holstein and rearing Korean calves indicated 47.4%, 26.4%, 18.2% and 6.3% incidence of trematoda infections, respectively. of trematoda positive cattle, 76.6% were infected with Fasciola spp., 4. The rate of Theileria and Babesia infection was 62.7% in the examined cattle. Of these positive cattle 5.4% were infected with both parasites, 57.3% with Theileria, and 1.3% of rearing Korean calves and 22.6% of Holstein were found to have parasitized erythrocytes over 1.0%. 5. The incidence of diseases in 1968 cattle of 240 herds was 564 cattle (28.7%) of 154 herds (64.2%). of the diseases observed of skin occurred in 354 cattle (18.0%) of 61 herds (25.4%), diseases of respiratory system in 121 cattle (6.1%) of 34 herds (14.2%), diseases of digestive system in 38 cattle (1.9%) of 22 herds (9.2%), diseases of eye in 21 cattle (1.1%) of 13 herds (5.4%), diseases of urogenital system in 8 cattle (0.4%) of 8 herds (3.3%) and the other diseases in 24 cattle (1.2%) of 22 herds (9.2%). 6. Diseases of skin in 1968 cattle of 240 herds werds were observed in the highest incidence. Ringworm was observed in 13.3% of the examined herds, rearing Korean calves and Holstein showed high incidence. Scabies caused by Chorioptes bovis and alopecia localis along with infestation of lice (Damalinia bovis, Linognathus vituli) were observed in fattening Korean cattlein winter. 7. Diseases of respiratory system occurred frequently in rearing Korean cattle and Holstein. In the diseases of digestive system acute indigestion occurred in fattening Korean cittle, enteritis in rearing Korean calves and Holstein, and coccidiosis in rearing Korean calves maninly. 8. Infectious keratoconjunctivitis occurred in a fattening Korean cattle herd, sterility (2.0%) in breeding Korean cows, and theileriosis in Holstein calves were also occurred. In addition, poisoning and heat stroke were observed in several cattle.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.320-329
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• 1997

Neuroanatomic substrate of autism has been the subjects of continuing investigation. Because previous studies had not demonstrated consistent and specific neuroimaging findings in autism and most studies comprised adults and school-aged children, we performed a retrospective review in search of common functional and anatomical abnormalities with brain SPECT using Tc-99m ECD and correlative MRI The patient population was composed of 18 children aged 28 to 89 months(mean age : 55 months) who met the diagnostic criteria of autism as defined in the DSM-IV and CARS. Brain SPECT was performed after intravenous injection of 185-370MBq of Tc-99m ECD using brain dedicated annular crystal gamma camera. MRI was performed in all patients including T1, T2 axial and T1 sagittal sequences. SPECT data were visually assessed. Thirteen patients had abnormal SPECT scan revealing focal areas of decreased perfusion. Decreased perfusion of cerebellar vermis(12/18), cerebellar hemisphere(11/18), thalami(13/18), basal ganglia(4/18), posterior parietal(7/18), and temporal(4/18) area were noted on brain SPECT. Whereas, only 3 patients had abnormal MR findings which were subtle volume loss of parieto-occipital white matter in 3 and mild thinning of posterior body of corpus callosum in 2 and slightly decreased volume of cerebellar vermis in 1. Comparison of the numbers of abnormal findings revealed that regional cerebral blood flow (rCBF) abnormalities seen on SPECT were more numerous than anatomical abnormalities seen on MRI. In conclusion, extensive perfusion impairment involving cerebellum, thalami and parietal lobe were found in this study. SPECT may be more sensitive in reflecting pathophysiology of autism than MRI. However, further studies are mandatory to determine the significance of thalamic and parietal perfusion impairment in autism.

• Korean Journal of Organic Agriculture
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• v.20 no.3
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• pp.411-422
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• 2012

To investigate the possibility of sustainable agriculture in no-tillage pepper this study was carried out in vinyl greenhouse with organic cultivation having no pesticide certification. 1. Growth and yield in pepper cultivation General growth in pepper was suppressed with decreasing hill spacing, primary branch length, and stem width. Fruit diameter and fruit weight in no-tillage increased significantly, and yield of pepper increased by 10% compared with conventional tillage. From results organic cultivation in no-tillage improved a quality of pepper compared with conventional tillage. 2. Production cost of conventional tillage and no-tillage Production cost of conventional tillage and no-tillage was not different in seed cost, inorganic fertilizer cost, pesticide cost, repair cost, light agricultural tool cost, agriculture facilities depreciation cost and so on. Intermediary goods cost in no-tillage was decreased by 11% for organic fertilizer cost, light and heat expenses and power rate, heavy agricultural tool cost, and repairing expenses compare with conventional tillage. Employment effort cost and work effort cost were decreased, and farm income and farm income rate were increased by 11% and 5%, respectively, in no-tillage. In this work, yield and gross income were increased by 10% and 25%, respectively, in no-tillage. Therefore material cost, intermediary goods cost, working expensive, farm income, and income rate were increased by 34%, 3%, 2%, 52% and 22%, respectively.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.295-301
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• 2004

Recently, the rapid increase and global spread of extended-spectrum $\beta-lactamase$ producing clinical isolates has become a serious problem. The incidence of extended-spectrum $\beta-lactamase$ producing clinical isolates of Escherichia coli in Korea and susceptibility to antimicrobial agents were investigated. Total 233 isolates of E. coli were obtained from urine from hospitalized patients in Guro hospital, Korea University in 2001. One hun­dred and eighty four isolates $(78.9\%)$ were resistant to ampicillin, 80 isolates $(34.3\%)$ were resistant to ceph­alothin, 93 isolates $(39.9\%)$ were resistant to gentamicin, and 64 isolates $(27.5\%)$ were resistant to norfloxacin. Among 233 isolates, 17 isolates $(7.3\%)$ were positive as determined by the double disk synergy test. When min­imal inhibitory concentrations were assayed with additional 6 antimicrobial agents, 13 isolates $(76.5\%)$ were multi-drug resistant to at least four different class antimicrobial agents. Extended-spectrum $\beta-lactamase$ were characterized with isoelectric focusing gel electrophoresis and DNA sequencing. They were TEM-1 in 5 iso­lates, TEM-15 in 1 isolate, TEM-20 in 1 isolate, TEM-52 in 4 isolates, TEM-1 and AmpC in 2 isolates, TEM-1 and OXA-30 in 1 isolate, TEM-1 and OXA-33 in 1 isolate, TEM-1, CTX-M-3, and AmpC in 1 isolate, but SHV was not detected. Antimicrobial resistance genes were transferred to animal isolate of E. coli (CCARM No. 1203) by the filter mating method. Extended spectrum $\beta-lactamase$ producers studied in the current study have low correlation to each other as determined by random amplified polymorphic DNA and pulsed field gel elec­trophoresis. This is a contradictory result from the general hypothesis that extended-spectrum $\beta-lactamase$ pro­ducers in one hospital is a result from a clonal spread.