• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.54-62
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• 2005

The present study was to determine how seasonal rainfall intensity influences nutrient dynamics, ionic contents, oxygen demands, and suspended solids in a lotic ecosystem. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of rainfall. Dissolved oxygen (DO) had an inverse function of water temperature (r = = = - 0.986, p<0.001). Minimum pH values of<6.5 were observed in the late August when rainfall peaked in the study site, indicating an ionic dilution of stream water by precipitation. Electrical conductivity (EC) was greater during summer than any other seasons, so the overall conductivity values had direct correlation (r = 0.527, p<0.01) with precipitation. Ionic dilution, however, was evident 4 ${\sim}$ 5 days later in short or 1 ${\sim}$ 2 weeks in long after the intense rain, indicating a time-lag phenomenon of conductivity. Daily COD values varied from 0.8 mg $L^{-1}$ to 7.9 mg $L^{-1}$ and their seasonal pattern was similar (r = 0.548, p<0.001) to that of BOD. Total nitrogen (TN) varied little compared to total phosphorus (TP) and was minimum in the base flow of March. In contrast, major input of TP occurred during the period of summer monsoon and this pattern was similar to suspended solids, implying that TP is closely associated (r = 0.890, p<0.01) with suspended inorganic solids. Mass ratios of TN : TP were determined by TP (r= -0.509, p<0.01) rather than TN (r= -0.209, p<0.01). The N : P ratios indicated that phosphorus was a potential primary limiting nutrient for the stream productivity. Overall data suggest that rainfall intensity was considered as a primary key component regulating water chemistry in the stream and maximum variation in water quality was attributed to the largest runoff spate during the summer monsoon.

• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.174-189
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• 2012

The objective of this study was to determine the weight-length relations and condition factor (K) of Zacco platypus, along the trophic gradients from oligotrophic to eutrophic state in six reservoir ecosystems ($B_aR$, $Y_yR$, $J_yR$, $G_pR$, $Y_dR$, and $M_sR$), during 2008~2010. The species was selected as a sentinel species for the study, due to its wide distribution and wide trophic gradient. The analysis of trophic state index (TSI), based on total phosphorus (TP) and chlorophyll-a (Chl-a), indicated that reservoirs of $Y_yR$ and $B_aR$ were classified as to be in an oligotrophic state (30~40), the $J_yR$ and $G_pR$ as mesotrophic (40~50), and the $Y_dR$ and $M_sR$ as eutrophic state (50~70). Total 47 species and 26,226 individuals were sampled from 6 reservoirs and sensitive species dominated in the oligotrophic reservoirs ($Y_yR$ and $B_aR$). In the mean time, the tolerant speciesdominated the community in the mesotrophic ($J_yR$ and $G_pR$) and eutrophic ($Y_dR$ and $M_sR$) reservoirs. Regression analysis of body weight, against the total length, indicated that the regression coefficient (b value) was lower in the oligotrophic reservoir (2.77~2.79) than the mesotrophic (3.07~3.17) and eutrophic reservoirs (3.15~ 3.21). This result suggests that the population growth rate Zacco platypus reflected the trophic gradients of the reservoirs. The analysis of condition factor (K) against the total length showed positive slopes (b>3.0) in mesotrophic and eutrophic reservoirs, and a negative slope (b<3.0) in oligotrophic reservoir. The variation of the regression slope of "b" in Z. platypus was accounted for 79.7% [$b=0.012{\times}TSI(TP)+2.395$, p=0.017] by the variation of TSI (TP) and 82.2% [$b=0.013{\times}TSI(Chl-a)+2.36$, p=0.013] by the variation of TSI (Chl-a). The proportion of DELT abnormality increased as the trophic state increases in the reservoirs. The overall data suggest that the growth of the fish populations, based on the length-weight relations and condition factor, reflected the trophic state of nutrient and phytoplankton biomass of the reservoir waters. Thus, in spite of the tolerant characteristics of Z. platypus, hypertrophic states might negatively affect the health of the population.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.1-15
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• 2017

Daecheong Reservoir was made by the construction of a large dam (>15 m in height) on the middle to downstream of the Geum River and the discharge systems have the watergate-spillway (WS), a hydropower penstock (HPP), and two intake towers. The purpose of this study was to investigate the limnological anomalies of turbid water reduction, green algae phenomenon, and oligotrophic state in the lower part of reservoir dam site, and compared with hydro-meteorological factors. Field surveys were conducted in two stations of near dam and the outlet of HPP with one week intervals from January to December 2000. Rainfall was closely related to the fluctuations of inflow, outflow and water level. The rainfall pattern was depended on the storm of monsoon and typhoon, and the increase of discharge and turbidity responded more strongly to the intensity than the frequency. Water temperature and DO fluctuations within the reservoir water layer were influenced by meteorological and hydrological events, and these were mainly caused by water level fluctuation based on temperature stratification, density current and discharge types. The discharges of WS and HPP induced to the flow of water bodies and the outflows of turbid water and nutrients such as nitrogen and phosphorus, respectively. Especially, when hypoxic or low-oxygen condition was present in the bottom water, the discharge through HPP has contributed significantly to the outflow of phosphorus released from the sediment into the downstream of dam. In addition, HPP effluent which be continuously operated throughout the year, was the main factor that could change to a low trophic level in the downreservoir (lacustrine zone). And water-bloom (green-tide) occurring in the lower part of reservoir was the result that the water body of upreservoir being transported and diffused toward the downreseroir, when discharging through the WS. Finally, the hydropower effluent was included the importance and dynamics that could have a temporal and spatial impacts on the physical, chemical and biological factors of the reservoir ecosystem.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.1
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• pp.37-42
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• 2009

This experiment was conducted to investigate the effect of cattle manure application on macro contents change in pasture. The treatment consisted of T1: 100% chemical fertilizer (CF 100%), T2: 50% CF+50% cattle manure (CM), T3: 25% CF+75% CM, T4: 100% CM 100%, T5: 100% CM(1st year (yr.) +100% CF (2nd yr.)+100% CM (3rd yr.), T6: 100% CM (1st yr.)+100% CF (2nd yr.)+100% CF (3rd yr.). The highest substitution effect of chemical fertilizer with cattle manure indicated by the highest yield of 11,169 kg/ha was obtained from the application of 100% CM (1 yr.) + 100% CF (2 yr.). The forage yield of plots applied with 100% CM (1 yr.) + 100% CF(2 yr.) was only 4% more than the yield of plots applied with 100% CM. It was only 3% less than the yield of plots applied with 100% CF. In this study, cattle manure application recorded slightly lower forage dry matter (DM) yield than 100% CF application but they were statistically comparable on the third year of production. The all treatments have narrow range of P, K, Ca, Mg and Na contents $0.25{\sim}0.32%,\;3.08{\sim}3.71%,\;0.42{\sim}0.55%,\;0.21{\sim}0.38%$ and $0.08{\sim}0.15%$.

• Korean Journal of Environmental Agriculture
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• v.31 no.4
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• pp.300-307
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• 2012

BACKGROUND: The Transfer Factor (TF) of heavy metals from soil to plant is important, because TF is an indicator of heavy metal in soils and a factor that quantifies bioavailability of heavy metals to agricultural products. This study was conducted to investigate the transfer ability of Arsenic (As), Cadmium (Cd), and Lead (Pb) from soil to agricultural products. METHODS AND RESULTS: We investigated heavy metals (As, Cd and Pb) concentrations in 9 agricultural products (rice, barely, corn, pulse, lettuce, pumpkin, apple, pear, tangerin) and soil. TF of agricultural products was evaluated based on total and HCl-extractable soil concentration of As, Cd, and Pb. Regression analysis was used to predict the relationship of total and HCl-extractable concentration with agricultural product contents of As, Cd, and Pb. The result showed that TF was investigated average 0.006~0.309 (As), 0.002~6.185 (Cd), 0.003~0.602 (Pb). The mean TF value was the highest as rice 0.309 in As, lettuce 6.185, pear 0.717, rice 0.308 in Cd, lettuce 0.602, pumpkin 0.536 in Pb which were dependent on the vegetable species and cereal is showed higher than fruit-vegetables in As. CONCLUSION(S): Soil HCl-extractable concentration of As, Cd, and Pb had the larger effects on thier contents in agricultural products than total soil concentrations. We suggests that TF are served as influential factor on the prediction of uptake. Further study for uptake and accumulation mechanism of toxic metals by agricultural products will be required to assess the human health risk and need TF of more agricultural products.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.3
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• pp.159-168
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• 2005

This experiment was carried out during the period from May to October 1998 to determine the effect of fermented sawdust swine manure application (SSM) on the herbage production of Japanese millet and soil properties in the Cheju brown volcanic ash soil. The randomized block design (T1 : basic chemical fertilizer, N 200 kg/ha + $P_2O_5\;300 kg/ha+K_2O$ 200kg/ha ; T2 : 1/2 basic chemical fertilizer, N $100+P_2O_5\;150+K_2O$ 100kg/ha; T3 : 1/2 basic SSM, N 100kg/ha, T4:basic SSM, N 200kg/ha; T5:2 times basic SSM, N 400 kg/ha ; T6:4 times basic SSM, N 800 kg/ha) was used. At the same application level of nitrogen 200kg/ha, the application of $100\%$ chemical fertilizer (T1) had significantly lower dry matter yield than that of $50\%$ chemical fertilizer and $50\%$ SSM (T2) or $100\%$ SSM (T4)(p<0.01). Dry matter yield increased with an increase of SSM application to N 400kg/ha level but decreased at N 800 kg/ha level. P, K and Ca contents of Japanese millet tended towards to decrease with an increase of SSM level. The application of chemical fertilizer lowered P and K content of Japanese millet in comparison with that of SSM (p<0.05). pH, available phosphorus. exchangeable potassium, Ca and Mg content of soil studied showed a significant increase with an increase of SSM application level (p<0.05). However, at the same application level of N 200kg/ha, there was statistically no significant difference between chemical fertilizer and SSM in those contents of soil after experiment. The bacterial number of soil among microbial population increased with an increase of SSM level, in June, 1998 (p<0.05), but there was no regular tendency, in October. The rate of bacteria to fungus in soil had a tendency to decrease with an increase of SSM level. In conclusion, it is recommended to use N 400kg/ha of SSM or N 100 kg/ha of chemical fertilizer+N 100 kg/ha of SSM for Japanese millet.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.81-88
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• 2008

The study was conducted to investigate the effects of DM (dry matter) content and split application of liquid swine manure (LSM) on productivity of rye and subsequent soil quality on the pasture of Livestock Policy Division, Jeju Special Self-Governing Province. The experiment was done between November, 2005 and June 2006, using split plot design. Treatments were 2 main plots (7.0 and 1.6% DM LSM) and 2 subplots (basal fertilizer 100% and basal fertilizer 50%+top dressing 50%). Application of 7.0% DM LSM resulted in significant increase in DM yield and plant length of rye compared with 1.6% DM LSM (p<0.05). Crude protein content of rye was significantly higher in split application(basal fertilizer 50%+ top dressing 50%) than in basal fertilizer 100% (p<0.05). No significant difference in macro and micro mineral contents of rye or in subsequent soil quality was found by application of LSM. Mean P content (0.16%) of rye appeared to be lower than proper P level $(0.2{\sim}0.4%)$ of grass crop. The pH (5.5), OM (13.3%), available $P_2O_5$ (47.6 mg/kg) and Ca (2.75cmole/kg) content of the pasture soil studied were lower, compared with those of cultivated soil. Results show that the application of a 7.5% DM liquid swine manure increases the productivity of rye compared with a 1.6% DM liquid swine manure, meanwhile the property of pasture soil was not influenced by application of LSM.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.291-303
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• 2020

Marine organism-derived toxins have negative effects not only on human health but also in aquaculture, fisheries, and marine ecosystems. However, traditional analytical methods are insufficient in preventing this threat. In this paper, we reviewed new rapid methods of toxin detection, which have been improved by adopting diverse types of nanomaterials and technologies. Moreover, we herein describe the main strategies for toxin detection and their related sensing performance. Notably, to popularize and commercialize these newly developed technologies, simplifying the process of pre-treating real samples real samples is very important. As part of these efforts, numerous studies have reported pretreatment methods based on the antibody-immobilized magnetic nanoparticles, and some cases have applied nanoparticles to enhance the sensing performance by utilizing the intrinsic catalytic activity. Furthermore, some reports have introduced fluorescent nanoparticles, such as quantum dots, to represent the lower detection limits of conventional enzyme-based colorimetric methods and lateral flow assays. Some studies using electrochemical measurements based on aptamer-nanoparticle complexes have also been announced. In addition, as the response to new toxins generated by changes in the marine environment is still lacking, further research on diagnostic and detection is also greatly needed for these kinds of marine toxins and their derivatives.

• Journal of Life Science
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• v.20 no.1
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• pp.147-152
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• 2010

Exercise-induced anaphylaxis (EIA) is a physical allergy, sometimes severe, triggered by exertion following specific food intake. It was defined for the first time in 1980. EIA is associated with different kinds of exercise. The clinical manifestations progress from itching, erythema and urticaria to some combination of cutaneous angioedema and vascular collapse. Mast cell participation in the pathogenesis of this syndrome has been proved by the findings of an elevated serum histamine level during exhaustive exercise. As predisposing factors of EIA, a specific or even nonspecific sensitivity to food has been reported. Food-dependent exercise-induced anaphylaxis (FDEIA) is a distinct form of food allergy induced by physical exercise. It is typified by the onset of anaphylaxis during exercise which was preceded by the ingestion of the causal food allergens. The diagnosis of FDEIA is heavily dependent on clinical history. Allergy tests may need to be performed using a broad panel of food and food additives. As with food allergies, FDEIA diagnosis is based on interview, biological test and skin test. Prophylaxis aims to prevent a recurrence; the patient should be given an emergency kit to deal with any recurrent episodes. After the food allergen has been identified, it should be avoided for at least 4 to 5 hours before any exercise. Two cases of EIA are presented (EIA to circumstances; FDEIA) in this paper, The diagnosis, pathophysiology and therapy of FDEIA are also reviewed.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.650-663
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• 2007

The purpose of this study was to identify the sanitation management items of school foodservice suppliers that require improvement, by assessing their sanitation practices with food commodities. Our field assessment was performed using a total of 20 vendors supplying agricultural products, meat products, seafoods and processed products; all were located in the Seoul and Gyeonggi areas. The assessment tool for sanitation management was composed of 93 checklist items and was used to evaluate seven different categories; the facility and environment, management of the facility and equipment, food materials management, process control, water management, personal hygiene management, and laboratory instrument management. A score of two was given for "satisfactory", one for "fair", and zero for "unsatisfactory". The overall average supplier score was 1.7/2.0 (85.8%). The score of the seafood vendors was highest at 1.9 (95.4%), while the lowest score of 1.3 (65.7%) occurred with the processed product suppliers. Among the sanitation management categories, water management was scored at 2.0, while inspection management was lowest at 1.4. The subcategories indicating needed improvements for the processed product suppliers were raw materials, storage, transport and recall. For the agricultural product suppliers it was preparation management. furthermore, one item within the laboratory instrument management category was unsatisfactory for both the agricultural and processed product suppliers. In conclusion, these results can be used to develop sanitation management procedures for suppliers, as well as by administration agencies to evaluate and guide those suppliers.