• Journal of agricultural medicine and community health
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• v.18 no.2
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• pp.131-140
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• 1993

This study was conducted to examine the levels of mercury in tissue of Carassius carassius collected at five areas(Andong, Sangju, Waekwan, Gangjung and Gaejin) in Nakdong river from February to March, 1993. The contents of total and organic mercury were determined by methods of Gold amalgam and Selective atomic absorption with mercury analyzer(Model SP-3A). The total mercury contents in muscle were $0.148{\pm}0.0646$ ppm by the Gold amalgam, and $0.113{\pm}0.0345$ ppm by the Selective atomic absorption, but in all parts of Carassius carassius were $0.342{\pm}0.4235$ ppm and $0.240{\pm}0.2974$ ppm respectively. These two methods were extremely high correlated(r=0.9812, p<0.001). The mean value of total and organic mercury by the two methods was high in the order of bone>fin>muscle, respectively, and the proportion of organic mercury to the total was 69.0%. Mean value of total and organic mercury in the muscle was the highest at Wakeman located in middle basin of Nakdong river, and in the bone and fin was the highest at Andong dam located in upper basin. According to sizes and parts of fish, the concentration of mercury was the highest in the muscle of 15-19 cm group, the highest in the bone of 10-14 cm group and in the fin of 20-24 cm group.

• 한국벤처창업학회:학술대회논문집
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• 2008.04a
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• pp.179-208
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• 2008

In this research, an empirical analysis was performed to determine the correlation between management performance and R&D investment for domestic venture businesses in each industry. Specifically, an empirical analysis for each industry was attempted not only to clarify the general hypothesis on the relationship between management performance and R&D investment for venture businesses but also to demonstrate that differences exist for each industry. Empirical analysis was conducted for eight industries with respect to the $2002{\sim}2006$ panel data extracted as investigative results from the "Investigation Report on Science and Technology R&D Activities" published by the Ministry of Science and Technology. Industrial classification was limited to the middle-level classification (2-digit) in the Korea Standard Industry Code (KSIC) owing to the limited number of panels. Although this research only verified the overall positive effect of R&D activities and funds for existing research on corporate value or productivity and management performance, it was able to document the difference for each individual industry and each business size unlike existing research.Furthermore, the reliability of the research results was enhanced by targeting companies that have been continuously conducting R&D and management activities using consistent 5-year panel data in the analysis. Again, this was something that existing research did not have. Finally, through the use of recent data from 2002 after the IMF economic crisis up to 2006 in the empirical analysis, this research proposed the problems due to the prevailing circumstances at the time of entering the advanced nation stage based on an empirical analysis; the prevailing problems during the pursuit of advanced nation status before the IMF crisis broke out were not tackled. The key empirical analysis yielded several results. First, capital and size of the labor force have a positive correlation with the management performance for the entire company or the venture business. This applies to all eight industries as the subjects of the analysis. Second, although the number of years since a company has been established can have positive or negative correlation with management performance for the entire company or venture business in specific industries, a definite overall trend cannot be identified. Third, R&D investment can be said to have an overall positive effect on corporate management performance. Fourth, the size of the research staff cannot be said to be a factor unilaterally affecting the management performance of the entire company or the venture business. Fifth, the number of years a research institute has been in operation, which was assumed to have a positive effect on the management performance of a company because of the accumulated R&D know-how -- definitely acts as a positive factor contributing to the management performance of a company.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.266-280
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• 1989

Gonadal maturation of the Korean pomfrets, Pampus echinogaster (Basilewsky) and Pampus argenteus (Euphrasen) were histologically investigated based on the samples captured in the East China Sea from January 1987 to December 1988. Gonadosomatic index (GSI) of P. echinogaster began to increase from March, and reached maximum between May and July. It began to decrease from July and reached mini-mum between August and February. P. argenteus had a similar cycle, however, P. argenteus has higher values in April than P. echinogaster. Hepatosomatic index (HSI) were positively related to GSI. HIS of P. echinogaster and P. argenteus reached maximum in $April\~July$ and $April\~August$, respectively, Fatness coefficient of two Pampus species were low in the summer, and high in the winter. Ovary is of saccular structure, and testis is of lobular structure. From February, the early oocyte (ca. $100\mu$ in diameter grows) rapidly at the germinal epithelium of ovarian sacs. From March to April the oocytes grew up to cu $400\~500\mu$ in diameter. At this stage, the yolk globules are accumulated rapidly in the cytoplasmic layer. From May, the oocytes roached ca. $650\~850\mu$ in diameter, and they are spawned in $May\~July$. After spawning the residual follicles and remained ripe eggs degenerate. From February, spermatogonia grows into spermatocyte on the epithelium of the testicular lobuli. From May, spermatozoa appeared and spawning occurs. After spawning, the epithelium is thickened and the remained spermatozoa degenerate. Annual reproductive cycle of two Pampus species could be divided into four successive stages: Growing stage ($March\~April$), Mature stage ($April\~May$), Ripe and spent stage ($June\~July$) and Recovery and resting stage ($August\~January$). Absolute fecundity of P. echinogaster was $9,441\~135,294$, and that of P. argenteus was $50,678\~221,894$. Absolute fecundity of two Pampus species were positively related to body length and total weight. Relative fecundity was positively related to body length, while it was reversely related to total weight. The increasing rate of absolute fecundity of P. echinogaster was lower than P. argenteus. In P. echinogaster half of female and male reached first maturity at body length of $15.0\~$17.9cm and $12.0\~14.9cm$, respectively. All of females and males reached first maturity at body length of $18.0\~20.9cm$ and $21.0\~23.9cm, respectively. In P. argenteus all of females and males reached first maturity at body length of 18.6cm and 16.7cm$, respectively.

• Journal of Nutrition and Health
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• v.44 no.5
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• pp.443-452
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• 2011

The characteristics of pesticide residues were examined in 18,069 samples from 91 vegetable commodities collected in Seoul from 2007 to 2009, and the vegetable dietary intakes of Seoulites were estimated using the Korea National Health and Nutrition examination survey data from 2008. The hazard index was calculated using vegetable pesticide residues and dietary vegetable intake by Seoulites. Detection rates for pesticide residues in vegetables were 11.2 % in 2007, 8.6 % in 2008, and 12.0 % in 2009. Excess rate of Maximum Residue Limits tended to decline from 4.6 % in 2007, to 2.8 % in 2008, and 2.1 % in 2009.Daily vegetable intake for Seoulites was 288.12 ${\pm}$ 214.8 g, and vegetable intake by males was more than that of females (p < 0.001). The hazard index was the highest at $2.76{\times}10^{-2}$ in 2007, and the lowest at $1.69{\times}10^{-2}$ in 2009. The risks caused by multiple pesticides in vegetables were very low and vegetable intake was safe considering the hazard index values.

• Journal of Korean Society of Forest Science
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• v.82 no.2
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• pp.188-194
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• 1993

A natural Quercus variabilis forest and a Populus alba${\times}$P. glandulosa plantation in Mt. Mohu area were studied to investigate aboveground biomass and net production. A $20m{\times}30m$ quadrat was set up in each stand, and 10 sample trees each of Quercus variabilis and Populus alba ${\times}$ P. glandulosa were cut for dimension analysis. There was little difference in accuracy among three biomass regression models of logWt=A+BlogD, $logWt=A+BlogD^2H$, and logWt=A+BlogD+ClogH, where Wt. D, and H were dry weight, DBH, and height, respectively. Aboveground total biomass of Quercus variabilis stand was 31,275kg/ha, and that of Populus alba ${\times}$ P. glandulosa was 55,581kg/ha. In both of Quercus variabilis stand and Populus alba ${\times}$ P. glandulosa stand, the proportion of each tree component to abovegound total biomass was high in order of stem wood, branches, stem bark, and leaves. Quercus variabilis stand was higher in the proportion of stem bark, branches and leaves than Populus alba ${\times}$ P. glandulosa stand, while the former was lower in that of stem wood than the latter. Aboveground total net production of Quercus variabilis stand was 4,267kg/ha/yr., and that of Populus alba ${\times}$ P. glandulosa stand was 3,903kg/ha/yr. The proportion of each tree component to aboveground total net production of Quercus variabilis stand was high in order of leaves, stem wood, branches, and stem bark. That of Populus alba ${\times}$ P. glandulosa stand was high in order of stem wood, leaves, branches, and stem bark. Net assimilation rate and efficiency of leaf to produce stem of Quercus variabilis stand were 2.121 and 0.840, respectively. Those of Populus alba ${\times}$ P. glandulosa stand were 3.376 and 2.085, respectively. Though Populus alba${\times}$P. glandulosa stand was lower in aboveground total net production than Quercus variabilis stand, the former was higher in aboveground total biomass than the latter. The reason was that Populus alba${\times}$P. glandulosa stand was higher in net production of stem wood of accumulation organs than Quercus variablis stand.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.335-343
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• 2006

This study was undertaken to investigate the effects of meal pattern on lipogenesis and activities of lipogenic enzyme in rats epididymal and mesenteric adipose tissues. A high fat diet was fed either ad libitum or in 1 meal during the last 3 h of the dark cycle for 4 weeks. Lipogenesis was measured as glucose conversion to total lipid and activities of glucose-6-phosphate dehydrogenase (G6PDH), 6-phophogluconate dehydrogenase (6PGDH) and NADP-malate dehydrogenase (ME) were determined by measuring NADPH production. Lipoprotein lipase (LPL) activity and serum lipoprotein concentrations were also measured. Meal-fed (3 h) rats had a decreased food intake, body weight and carcass fat compared with rats fed ad libitum. The serum triglyceride concentration of meal-fed rats tended to be higher than that of the ad libitum rats. However, there were no differences between meal-fed group and ad libitum group in serum concentrations of HDL-cholesterol, LDL-cholesterol and total-cholesterol. Rates of lipogenesis in both epididymal and mesenteric adipose tissues were significantly higher in the meal-fed group than that in the ad libitum group. In addition, meal-fed group showed higher G6PDH, 6PGDH and LPL activities in both epididymal and mesenteric adipose tissues, but exerted no significant effect on ME activity. These results suggest that meal-fed rats compared with ad libitum rats have marked lipogenic capacity, although such elevation probably does not result in increase in carcass fat concentration. Thus, meal-fed diet can be an important determinant of the alterations in adipose lipid metabolism.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.51-63
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• 2015

In order to investigation long-term variations of water qualities in the Saemangeum Salt-Water Lake formed after the sea-dike construction, the survey has carried out over 40 time from 2002 to 2010. The decreased salinity in surface water immediately after the dike construction has maintained on equal terms for years. After the dike construction, the early concentration of SPM in surface water has decreased but then it showed the tendency to move up and down due to the changes of water level in the lake. The elevated concentration of Chl-a in surface water initially after the dike construction was kept at the same conditions for years. The concentration of DIN in surface water has not changed before and shortly after the dike construction. However, the concentration of $NH_4-N$ in surface water has increased steadily after the dike construction. Consequently the concentration of DIN in the lake water after years has raised compared to pre-dike construction. The reduced concentration of DIP in surface water soon after the dike construction has increased after years as well as $NH_4-N$ due to the accumulation of organic matter to inside lake. Unlike with the unvaried $NO_3-N$, the concentration of DISi in surface water after the dike construction has immediately increased and maintained the enhanced level indicating the supply from other sources except the freshwater. Since the dike construction, the spatial characteristics of water quality was divided river sides and rest of the lake markedly. Stratification of river sides was more strong than the dike sides. In the warm seasons, hypoxia causing the release of nutrients and metals from sediment was observed downward about 1 m from surface of river sides. We strongly suggest to make some urgent measure to prevent low dissolved oxygen condition in the bottom layer of the river sides.

• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.389-398
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• 2010

The objective of this study was to investigate the effects of three strains of Bacillus subtilis (B. subtilis) supplemented to diets on egg production, egg quality, egg yolk cholesterol levels, the profile of cecal microflora, and tibia characteristics in laying hens. One hundred sixty 76-week-old Hy-Line Brown layers were randomly divided into 4 groups with 4 replicates per group (10 birds per replicate). Birds in the control group were fed a corn-soybean meal based diet. The remaining three treated groups were fed the control diet containing either 0.05% B. subtilis Ch3 (T1), 0.05% B. subtilis Ch3 + B. subtilis W1 (T2) or 0.05% B. subtilis commercial product (T3) for 6 weeks, respectively. There were no differences in feed intake, egg weight, egg production and egg mass among the groups. The dietary supplementation of B. subtilis improved eggshell strength and Haugh units compared to those of control (P<0.05). The activities of GOT and GPT in serum were not also affected by the dietary treatments. The population of total microbes and lactic acid bacteria in cecum were significantly increased by the dietary B. subtilis (P<0.05), but not the coliforms. The cholesterol concentration in egg yolk and serum in the treated groups were significantly decreased compared to those of control (P<0.05). Also, The levels of phospholipids in serum were significantly decreased compared to those of control (P<0.05). The supplementation of three strains of B. subtilis to diets significantly increased the contents of tibia ash compared to that of control (P<0.05). Thus, this study showed significant improvements in egg quality, such as eggshell strength and Haugh unit, by dietary B. subtilis strains. The B. subtilis strains added to the diets modulated the profiles of cecal microflora, reflecting beneficial effects in laying hens.

• Journal of Preventive Medicine and Public Health
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• v.27 no.1 s.45
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• pp.44-58
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• 1994

This study was conducted to examine the levels of total and organic mercury in the scalp hair of the elementary school children and adults, and their relationship with the consumption pattern of fishes and shellfishes. The scalp hair samples were collected from the occipital part of 115 children and 131 adults in costal, urban and rural areas of Kyungpook province from June to August 1991. The mercury content was analysed by the atomic absorption spectrophotometer (model IL. 555) with atomic vapor accessory (model IL. 440). The total and organic mercury contents of hair were significantly higher (p<0.01) among the children who prefer fish and/or shellfish (7.728 ppm, 6.610 ppm), and canned fish and/or fish pastes (6.969 ppm, 5.885 ppm) than those who prefer meat (4.822 ppm, 3.905 ppm) and vegetables (3.974 ppm, 3.224 ppm). The children who prefer to eat the canned fish without cooking showed a higher mercury content than the children who prefer to eat it as stew or mixed with vegetables (p<0.01). There was a dose-response relationship between the intake frequency of canned fish, raw fish and cooked fish and the content of total and organic mercury of hair, the children who eat fish almost everyday showed 2 times higher than those who eat rarely (p<0.01). The mercury content in the hair of the children who eat raw fish was significantly higher than that of the children who eat boiled or broiled fish (p<0.01). The total and organic mercury contents of adult scalp hair increased with age up to the forties and slightly decreased in the fifties. The mercury contents of those who were engaged in the fishery and raw fish restaurant were 2 times higher than those of the farmers. The mercury content of the persons who were favorite dishes of fish and shellfish were most high, and who prefer raw fish were 2 times higher than those of the persons who prefer vegetables and broiled fish. The contents of total and organic mercury in adult scalp hair showed also a increasing tendency with the intake frequency of raw and cooked fish.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1098-1103
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• 2003

Soybeans released proteins when immersed in water at $50{\sim}60^{\sim}C$. We investigated the changes in the characteristics of soybean when soaked in water at different temperatures and studied the electrophoretic properties of soy proteins in recommended Korean soybean varieties after heat treatment. Soybean seeds were heated in soaking water at temperatures of 30, 40, 50, 60, $70^{\circ}C$ for 90 min, and also from 10 to 150min at $60^{\circ}C$. The pH value of the water decreased with heating time at $60^{\circ}C$, and the amount of soluble solids increased with temperature and heating time. The protein concentration of the solution increased with temperature and time. From SDS-PAGE of the proteins in soaking water, we detected two new bands of 16 kDa- and 31 kDa-proteins from the Korean soybean varieties on heat treatment.