• Asian Journal of Atmospheric Environment
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• v.10 no.4
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• pp.169-178
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• 2016

Measurements of $SO_2$, $NO_2$ and benzene, toluene, ethylbenzene, and xylenes BTEX concentrations using passive tubes were carried out at five locations featuring educational and light industrial activities in south western Kuwait City during 2014. The five selected sites, chosen to be statistically representative of land use in the study area, were monitored to evaluate the impacts of traffic and light industrial activities on pollutant concentrations. The recorded mean concentrations of $NO_2$, $SO_2$ and BTEX were 40.3, 28.1 and $3.72{\mu}g/m^3$, respectively. The lowest concentrations were recorded in the educational area. Comparisons between the measured concentrations and the applicable air quality standards from the Kuwait Environment Public Authority showed that the gas concentrations were lower than the allowable limits.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.2
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• pp.153-160
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• 1998

The concentrations of volatile organic compounds (VOCs) in the atmosphere were measured from the Yochon Industrial Estate and compared with those from Tongkwangyang and Seoul. The first important phenomenon observed in the air of Yochon was high concentrations of alkenes and in particular, ethylene and propene. For most dominant species, their means and standard deviations were high simultaneously. Concentrations of several major aliphatic species exhibited a similar pattern of diurnal variation, however, with different species combination on each day. Concentrations of several hazardous aromatic species also exhibited a similar pattern of diurnal variation on the same day, which was different from that observed in the diurnal variation of major aliphatic species. It was interpreted that some species were intermittently released from relevant processes. It was also understood that high concentrations and variations of VOC species in Yochon were localized and not related to high average concentrations of ozone in Yochon and Tongkwangyang areas.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.379-382
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• 2002

The present study was to investigate Pb and Cd concentrations in tissues of feral pigeons in urban areas. The Pb levels in bones and livers did not differ between Seoul and Kwangju areas. However, there were significant differences in kidney and liver Cd concentrations between the study sites. These are thought to be a reflection of the metal exposure conditions in the local environment. In particular, metal levels from Seoul were compared with those obtained in the same area between 1991 and 2000 in terms of the long-term biomonitoring approaches. The mean Pb concentrations in bones decreased from 59.1 $\mu$g/wet g in 1991 to 29.5 $\mu$g/wet g in 2000, totaling a reduction in concentrations of approximately 50 percent. However, there were no significant differences in the liver Pb concentrations. Concentrations of Cd in livers and kidneys did not differ between 1991 and 2000.

• Journal of Nutrition and Health
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• v.26 no.9
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• pp.1098-1109
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• 1993

The purpose of this study was to investigate macro-mineral contents in human milk longitudinally from 2 days to 12 weeks postpartum. Milk samples were collected from 34 healthy lactating women. Calcium, Phosphorus, magnesium, sodium and potassium were analyzed. Concentrations of the minerals except for magnesium differed significantly within the lactation period. The levels of sodium and potassium declined linearly over the first 12 weeks of lactation, but that of phosphorus increased. Statistically significant quadratic trends were observed in phosphorus and sodium concentrations. There was no significant correlation between maternal age and mineral concentrations throughout the lactations period. In addition, no significant differences were found between the primipara and the multipara for mineral concentrations in human milk. Mineral intake of lactating women did not affect the individual mineral concentrations of milk. However, the protein and fat intake of lactating women had a significant correlation with sodium and potassium concentrations. The following four pairs of minerals : potassium and calcium, potassium and phosphorus, sodium and magnesium, and calcium and phosphorus showed a positive correlation with each other in human milk.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1614-1623
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• 2015

The objectives of the current experiment were to study the response of the growth performance of early finishing gilts to different net energy (NE) concentrations in diets, and to compare the NE values of diets between calculated NE values and measured NE values using French and Dutch CVB (Centraal Veevoederbureau; Central Bureau for Livestock Feeding) NE systems. In a metabolism trail, the NE concentrations in five diets used for the growth trial were determined based on digestible nutrient concentrations, digestible energy, and metabolizable energy using a replicated $5{\times}5$ Latin square design with 10 barrows (initial body weight [BW], $39.2{\pm}2.2kg$). In a growth trial, a total of 60 early finishing gilts (Landrace${\times}$Yorkshire; initial BW, $47.7{\pm}3.5kg$) were allotted to five dietary treatments of 8.0, 9.0, 10.0, 11.0, and 12.0 MJ NE/kg (calculated, as-is basis) with 12 replicate pens and one pig per pen in a 42-d feeding experiment. The NE and amino acid (AA) concentrations in all diets were calculated based on the values from NRC (2012). Ratios between standardized ileal digestible AA and NE concentrations in all diets were closely maintained. Pigs were allowed ad libitum access to feed and water. Results indicated that calculated NE concentrations in diets (i.e., five dietary treatments) were close to measured NE concentrations using French NE system in diets. The final BW was increased (linear and quadratic, p<0.05) with increasing NE concentrations in diets. Furthermore, average daily gain (ADG) was increased (linear and quadratic, p<0.01) with increasing NE concentrations in diets. There was a quadratic relationship (p<0.01) between average daily feed intake and NE concentrations in diets. Feed efficiency (G:F) was also increased (linear, p<0.01) as NE concentrations in diets were increased. The NE intake per BW gain (kcal NE/kg of BWG) was increased (linear, p<0.01) with increasing NE concentrations in diets that were predicted from both French and Dutch CVB NE systems. Linear regression indicated that predictability of daily NE intake from the BW of pigs was very low for both French ($R^2$, 0.366) and Dutch CVB ($R^2$, 0.374) NE systems. In conclusion, increasing NE concentrations in diets increase BW, ADG, G:F, and NE intake per BW gain of early finishing gilts. The BW of early finishing gilts is not a good sole variable for the prediction of daily NE intake.

• Korean Journal of Biological Psychiatry
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• v.2 no.2
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• pp.266-274
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• 1995

We invesigated whether the circadian rhythms of plasma MHPG and HVA concentrations exist in 11 healthy young adults, and analyzed the patterns of their circadian rhythms. The results were as follows : 1) The change in the mean plasma MHPG concentrations analyzed by repeated measures ANOVA was not statistically significant. Five subjects showed significant circadian rhythms of plasma MHPG concentrations of each individual, and 4 of those had the acrophases between 17PM and 24PM. 2) The change in the mean plasma HVA concentrations analyzed by repeated measures ANOVA was not statistically significant. Six subjects showed significant circadian rhythms of plasma HVA concentrations of each individual, and 4 of those had the acrophases between 21PM and 6AM. In conclusion, the circadian rhythm pattern of plasma HVA concentrations in our result is consistent with the previous study. It was suggested that plasma MHPG and HVA concentrations should be measured more frequently, and the physical activities of subjects be controlled more strictly for the following study.

• The Korean Journal of Ecology
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• v.20 no.1
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• pp.51-59
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• 1997

To investigate the distribution of heavy metal concentrations in Onsan bay, concentrations of cadmium, copper, zine and lead in surface sediments and the periwinkles (Littorina brevicula) were determined in Feburary and July, 1996. The ranges of cadmium, copper, zinc and lead concentrations in the surface sediments were 0.08-3.72, 3-307, 49-1273 and 15-399 ${\mu}g/g$ dry weight, respectively, The decrease of concentration in heavy metals with distance from Daejeong stream indicated that this stream is the pollutant source of heavy metals in Onsan Bay. The concentrations of cadmium, copper, zinc and led in L. brevicula were 0.11-11.81, 21-212, 30-96 and 0.26-4.12 ${\mu}g/g$ dry weigth in February and 1.01-24.9, 66-325, 54-225 and 0.68-8.41 ${\mu}g/g$ dry weight in July, respectively. These concentrations in L. brevicula were the significantly different (p<0.001) with the season of sampling. However, overall distribution of concentrations of heavy metals in L. brevicula had very similar tendency that concentrations of heavy metal decreased with the distance from the pollutant source irrespective of the two seasons. Therefore, L. brevicula is considered as a useful indicator for heavy metals pollution, According to analysis of the organs, tissues such as the digestive gland, gill and viceral mussel accumulate high concentrations of heavy metals.

• Journal of Korean Society of Forest Science
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• v.97 no.2
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• pp.181-186
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• 2008

Even small changes in phosphorus concentrations in stream water could cause eutrophication because of very low level of phosphorus concentrations in natural waters. I investigated the impact of strip cut and clear cut on phosphorus concentrations in stream water at the Hubbard Brook Experimental Forest and investigated stream water phosphorus concentrations as a function of flow rate and season (as well as cutting history). Mean phosphate concentrations in the control (undisturbed forest) increased $1.9{\mu}g\;L^{-1}\;to\;2.6{\mu}g\;L^{-1}$, while strip cut treatment increased phosphate concentrations in stream water $2.2{\mu}g\;L^{-1}\;to\;3.7{\mu}g\;L^{-1}$ during the same period. There was no significant effect of clear cut treatment on phosphate concentrations in stream water. No relationships were found between discharge rate and phosphate concentrations, but the magnitude of fluctuation were increased during two decades in undisturbed forest: $1-5{\mu}g\;L^{-1}$ from 1963 to 1975 and $1-12{\mu}g\;L^{-1}$ from 1983 to 1995. Based on this study, forest harvests with buffer zone will not make a problem by imported phosphate to cause eutrophication in natural water.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.2
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• pp.231-245
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• 2003

Hourly PM$_{10}$ concentrations measured at 11 sites in Seoul and 10 sites in the large cities over South Korea for the period from March 1995 to February 2000 are analyzed to examine annual trend and monthly variations of the PM$_{10}$ concentrations. Further analysis has been carried out by using the one year data from March 1999 to February 2000 to see the seasonal variation, diurnal variation and weekly variation of the seasonally averaged PM$_{10}$ concentrations at each site. Weekly variations of the CO concentrations at the same sites for the same one year period are compared with that of the PM$_{10}$ concentration. There is no significant annual trend in the variation of the PM$_{10}$ concentration at all the sites analyzed. The seasonal and monthly mean concentrations show a minimum concentration in summer and alternative maximum concentration in spring and winter for most sites. The diurnal variation of the seasonally averaged mean PM$_{10}$ concentrations is strongly affected by traffic loads and meteorological conditions. The weekly variation of seasonal averaged concentrations of CO and PM$_{10}$ shows a high concentration for weekdays in spring, autumn and winter while high concentration for weekends in summer.nds in summer.

• Journal of Nutrition and Health
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• v.31 no.3
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• pp.271-278
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• 1998

Folate coenzymes are involved in one-carbon transfer reactions needed for the synthesis of nucleic acids, amino acids, and proteins which are very important for cell proliferation and differentiation. To investigate the effects of dietary folate content on plasma and tissue folate concentrations and on folate excretions in urine and feces, male Sprague-Dawley rats were raised for 4-10 weeks on semi-purified experimental diets containing 0mg, 2 mg, 8mg folate/kg diet. Folate concentrations were determined microbiologically using Lactobacillius casei (ATCC 7469). When compared to the folate adequate diet, the folate deficient diet decreased folate levels in plasma, liver and kidney , and the values were further decreased with experimental period. In rats reviving folate supplemented diets, plasma , liver and kidney folate adequate or supplemented diets, folate concentrations weer increased compared to animals on the folate adequate diet. In the folate adequate or supplemented diets, folate concentrations in the plasma and kidney were maintained at essentially the same level for 10 weeks . Folate concentrations in the liver, however, continued to increase with experimental period. Dietary folate intake seems to influence plasma and liver folate concentrations more than kidney folate concentrations. Folate excretions unrine and feces were significantly increased with dietary foalte intakes and experimental period. Folate excreted via urine was consideerably greater than that via feces. These resutls indicated that the foate supplemented diet improved plasma and tissue foalte status. Whether folate supplmentation improves foalte-dependent reactions remains to be researched.