• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.1
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• pp.21-29
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• 2013

The studies were conducted to investigate real condition of mycotoxin contamination in the fields before harvest and by the storages of rice straw used as roughage in Korea. It was found mycotoxin contamination before harvest of rice straw that the rice plants were detected deoxynivalenol at the initial growth, ochratoxin A and deoxynivalenol at the middle growth, and deoxynivalenol and zearalenone at the harvest periods in the fields. Also, the rice plants were contaminated by various fungi such as Fusarium sp., Fusarium proliferatum, Penicillium sp., Gibberella sp., Gibberella zeae, Mucor circinelloides and Aspergillus oryzae. The levels of fungal contamination were $10^{3-4}$ cfu/g at the initial growth, and $10^{4-5}$ cfu/g at the middle growth and harvest periods. All storage types of rice straw were contaminated with zearalenone, deoxynivalenol and ochratoxins A. The samples of rice straw contaminating mycotoxins were account for 3% in bundle rice straw, and 38% in both types of square rice straw and rice round bale silage, respectively. When 105 samples of rice bale silage were analyzed for mycotoxins depending on the regional area, mycotoxin contamination was found in 46% of total samples in Korea. Regional contaminations of mycotoxins were respectively 48, 33, 40, 50 and 57% of samples in Gyeonggi, Gangwon, Chungcheng, Yeongnam and Honam area. Rice round bale silage was contaminated by three kinds of mycotoxins (zearalenone, deoxynivalenol and ochratoxinsA) in the all of area without Chungcheong area where was contaminated zearalenone and deoxynivalenol. Ochratoxins A, deoxynivalenol and zearalenone were respectively determinated with the average levels of 2.6, 413 and $338{\mu}g/kg$ in rice round bale silage for the overall area, even if it was some difference depending on each regional area. Therefore, the above results clearly show that the rice straws were exposed to the contamination by mycotoxin and mycotoxigenic fungi before harvest in the fields, and mycotoxin contamination was not dependent on the regional area or the storage types such as bundle rice straw, square rice straw and rice round bale silage.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.864-871
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• 2014

Seed viability is affected by storage conditions and rapid loss of viability in storage is the major cause for low germination. This study was carried out to examine the effect of packaging materials and storage temperature on seed germination rate over 10 years in two species (Capsicum annuum L. and Brassica rapa L. ssp. pekinensis) and determine effective storage conditions for maintaining seed viability. Seeds were packaged in aluminum poly pouches under vacuum, polyethylene bottles, and paper bags containing silica gel and stored under one of two controlled conditions ($15^{\circ}C$, RH 40% or $5^{\circ}C$, RH 30%) or at ambient condition. Seed germination was recorded at 6-month intervals for 10 years. The seeds of both species showed no decline in viability until 6.5 years at 15 or $5^{\circ}C$, irrespective of packaging materials. However, under ambient conditions, the seeds of chili pepper and Chinese cabbage in paper bags lost viability after 4 and 5 years, respectively. By contrast, seeds of both species in vacuum-aluminum poly pouches exhibited a 99% germination rate after 6 years under ambient conditions. Pepper seeds in the vacuum-aluminum poly pouches maintained a 93% germination rate after 10 years in ambient conditions. These results indicated that a special seed storage facility for maintaining viability of chili pepper and Chinese cabbage seed might not be essential and seed testing would not be necessary for 10 years, if chili pepper and Chinese cabbage seeds were packed in ambient/vacuum-aluminum poly pouches or $5^{\circ}C$/vacuum-aluminum poly pouches.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.109-118
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• 2000

The dynamics of inorganic nutrients and phytoplankton population were examined at eight stations of Shihwa Reservoir, which situated near the cities newly constructed and the industrial complex of West-sea in Korea, from January to December 1999. Among environmental factors, average concentration of $NH_4$, SRP and SRSi were $522.7\;{\mu}g\;N/l$, $9.8\;{\mu}g\;N/l$ and $0.26\;{\mu}g\;Si/l$, respectively. Water quality was extremely deteriorated by a great amount of pollutants load into inner reservoir after the event of rainfall. Nutrients concentration was suddenly decreased toward the lower part. While $NO_3$ concentration did not much varied among stations, but it was relatively high in winter season. Chlorophyll-a concentration was high at the upper part of the reservoir, with average of $37.2\;{\mu}/l$, and closely related to the fluctuation of $NH_4$, SRP and SRSi concentrations. The phytoplankton development in the water column was dominated by diatom (autumn), prasinoid (winter) and dinoflagellate (summer). Dominant phytoplankton were composed to Skeletonema costatum of diatom, Prorocentrum minimum of dinoflagellate, Chroomonas spp. of cryptomonad, Eutreptiella gymnastica of euglenoid and Pyramimonas spp. of prasinoid. The large bloom of phytoplankton at the upper zone of the Shihwa Reservoir after inflow of a seawater were consistently observed. In consequence, water quality management of the inlet stream was assessed to be very important and urgent.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.229-237
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• 2015

This study aims to offer basic data to effectively preserve and manage pine forests using more precise pine forests' distribution status. In this regard, this study predicts the geographical distribution change of pine forests growing in South Korea, due to climate change, and evaluates the spatial distribution characteristics of pine forests by age. To this end, this study predicts the potential distribution change of pine forests by applying the MaxEnt model useful for species distribution change to the present and future climate change scenarios, and analyzes the effects of bioclimatic variables on the distribution area and change by age. Concerning the potential distribution regions of pine forests, the pine forests, aged 10 to 30 years in South Korea, relatively decreased more. As the area of the region suitable for pine forest by age was bigger, the decreased regions tend to become bigger, and the expanded regions tend to become smaller. Such phenomena is conjectured to be derived from changing of the interaction of pine forests by age from mutual promotional relations to competitive relations in the similar climate environment, while the regions suitable for pine forests' growth are mostly overlap regions. This study has found that precipitation affects more on the distribution of pine forests, compared to temperature change, and that pine trees' geographical distribution change is more affected by climate's extremities including precipitation of driest season and temperature of the coldest season than average climate characteristics. Especially, the effects of precipitation during the driest season on the distribution change of pine forests are irrelevant of pine forest's age class. Such results are expected to result in a reduction of the pine forest as the regions with the increase of moisture deficiency, where climate environment influencing growth and physiological responses related with drought is shaped, gradually increase according to future temperature rise. The findings in this study can be applied as a useful method for the prediction of geographical change according to climate change by using various biological resources information already accumulated. In addition, those findings are expected to be utilized as basic data for the establishment of climate change adaptation policies related to forest vegetation preservation in the natural ecosystem field.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.441-451
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• 2017

The present study was conducted from August to December 2016 in a cylindrical water tank with a diameter of 1 m, a height of 4 m and a capacity of 3,000 L. The field water and sediment from the Nakdong River were also sampled for the experimental culture (field water+sediment) and control culture (field water), respectively. In this study, we aimed to investigate phytoplankton succession pattern using the phytoplankton functional group in the enclosed culture system. A total of 50 species in 27 genera including Chlorophyceae (30 species), Bacillariophyceae (11 species), Cyanophyceae (7 species), and Cryptophyceae (2 species) were identified in the experimental and control culture systems. A total of 19 phytoplankton functional groups (PFGs) were identified, and these groups include B, C, D, F, G, H1, J, K, Lo, M, MP, N, P, S1, $T_B$, $W_0$, X1, X2 and Y. In particular, $W_0$, J and M groups exhibited the marked succession in the experimental culture system with higher biovolumes compared to those of the control culture system, which may be related to the internal cycling of nutrients by sediment in the experimental culture system. The principal component analyses demonstrated that succession patterns in PFG were associated with the main environmental factors such as nutrients(N, P), water temperature and light intensity in two culture systems. In conclusion, the present study showed the potential applicability of the functional group for understanding the adaptation strategies and ecological traits of the phytoplankton succession in the water bodies of Korea.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.4
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• pp.350-358
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• 2017

The hemolysis index (HI) is semi-quantitative marker for hemolysis. Because the characteristics of the HI vary from one commercial platform to another, no standardization or harmonization of the HI is currently available. Specimens (N=40) randomly selected from clinical patients were artificially hemolyzed in vitro. The serum of the specimens was then diluted with a 20 mg/dL difference between 0~300 mg/dL based on serum hemoglobin measured using the XE-2100 hematology automation equipment (Sysmex, Japan). Diluted serum was measured using the Hitachi-7600 biochemical automation equipment (Hitachi, Japan) to differentiate between HI and serum hemoglobin. The data showed linearity between HI and serum hemoglobin and that HI 1 contained approximately 20 mg/dL of serum hemoglobin. To determine the blood rejection threshold, the HI was divided into three groups: HI 0~1, HI 4~6, HI 9~15. After another batch of clinical specimens (N=40) was measured using a Hitachi-7600 (Hitachi, Japan), each specimen was moved forward and backward with the piston of the syringe to induce an artificial in vitro hemolysis, then measured again with a Hitachi-7600 (Hitachi, Japan). The percentage difference between the three groups was analyzed by ANOVA or the Kruskal-Wallis test. In the post-test, there were significant differences between the HI 0~1 and the HI 5~6: Glucose, creatinine, total protein, AST, direct bilirubin, uric acid, phosphorus, triglyceride, LDH, CPK, Magnesium, and potassium levels. Because many clinical tests differed significantly, the threshold for hemolysis could be appropriate for HI 5 (serum hemoglobin 100 mg/dL).

• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.93-100
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• 2003

Objectives : Because shipyard workers are involved with various manufacturing process, they are exposed to many kinds of hazardous materials. Welders especially, are exposed to bisphenol-A (BPA) during the welding and flame cutting of coated steel, This study was conducted to assess the exposure status of the endocrine disrupter based on the job-exposure matrix. The effects of the genetic polymorphism of xenobiotic enzyme metabolisms involved in the metabolism of BPA on the levels of urinary metabolite were investigated. Methods : The study population was recruited from a shipyard company in the f province. A total of 84 shipbuilding workers 47 and 37 in the exposed and control groups, respectively, were recruited for this study. The questionnaire variables included, age, sex, use of personal protective equipment, smoking, drinking and work duration. The urinary metabolite was collected in the afternoon and correction made for the urinary creatinine concentration. The of the CYP1A1, CYP2E1 and UGT1A6 genotypes were investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods with the DNA extracted from venous blood. Results : The urinary BPA level in the welders group was significantly higher than in the control group (p<0.05). The urinary BPA concentration with the wild type UGT1A6 was higher than the other UGT1A6 genotypes, but with no statistical significant. From themultiple regression analysis of the urinary BPA, the regression coefficient for job grade was statistically significant (p<0.05). Conclusions : The grade of exposure to BPA affected the urinary BPA concentration was statistically significant. However, the genetic polymorphisms of xenobiotics enzyme metabolism were not statistically significant. Further investigation of the genetic polymorphisms with a larger sample size is needed.

• Childhood Kidney Diseases
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• v.12 no.2
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• pp.170-177
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• 2008

Purpose : The aim of this study was to evaluate whether the incidence of relapse or nephritis might be influenced by the duration of corticosteroid therapy in children with Henoch-Schonlein purpura(HSP). Methods : We retrospectively analyzed 186 children with a diagnosis of HSP in two major hospitals in Ilsan, Korea from the years 2000 to 2003. To evaluate whether renal involvement or relapse might be influenced by the duration of corticosteroid therapy in children with HSP, one pediatric nephrologist from hospital A, maintained corticosteroid therapy for at least 2 weeks(Group A, n=94). The other from hospital B used only during the symptomatic period(Group B, n=92). Results : There were no significant differences in age, sex, body weight, white blood cell count, hemoglobin, hematocrit, platelet count, serum protein and albumin levels between the two groups. The incidence of abdominal pain or arthralgia also did not differ between two groups. However, the duration of steroid therapy was significantly longer in Group A than in Group B and the cumulative dose of prednisolone was also higher in Group A than in Group B. The development of nephritis was more frequent in Group A. Conclusion : The longer duration of steroid use was not associated with the decreased rate of nephritis. Therefore, corticosteroids should be used carefully in a selected group of HSP children, and be tapered rapidly after control of the acute symptoms.

• Korean Journal of Soil Science and Fertilizer
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• v.13 no.2
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• pp.57-63
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• 1980

The effect of particle size of silicate fertilizer, crushed slag from the steel industry, on the behavior of silicate in soil was investigated through laboratory experiments. The silicate fertilizer was sieved to obtain three fractions of particles, coarser than 10 mesh 20-35 mesh, and finer than 100 mesh. Silicate concentration of the extract obtained by shaking 20 mg of particles, coarser than 10 mesh, 20-35 mesh, and finer than 100 mesh, in 50 ml of distilled water for 4 hours was 0.3, 1.0, and 3.2 ppm respectively. As shaking the mixture of the silicate fertilizer and soil proceeded, silicate concentration of the extract increased, and this increase after 4 hour shaking was attributed mainly to dissolution of soil silicate. When the mixture of soil and the silicate fertilizer was incubated under submerged condition, silicate concentration of the solution decreased for the first 2-4 weeks, thereafter increased with incubation time. During this incubation period, silicate concentration of the solution changed inversely with pH of the solution. After 6-10 weeks, however, both silicate concentration and pH of the solution increased with incubation time. Silicate concentration of the effluent from the 14.5 cm soil column of which top 4.5 cm was packed with the mixture of 30 g of soil and 30 mg of the silicate fertilizer reached maximum at 0.94 pore volumes for the particles of 20-35 mesh and 1.03 pore volumes for the particles finer than 100 mesh, whereas the effluent concentration reached maximum at 0.88 pore volumes for the soil column without the silicate fertilizer treatment. Soil analysis made after water percolation revealed that 1.5 pore volumes of water could leach down large amount of the water soluble silicate but not the sodium acetate extractable silicate, from top 3-6 cm soil layer.

• Journal of the Korean Society of Radiology
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• v.9 no.3
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• pp.147-168
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• 2015

In this research, we have analyzed the impact factors on the bone mineral density thru the examination of bone density difference in the entire femur, femoral neck and lumbar of adult women before the menopause in accordance with the general features, lifestyle, eating habits, health and body composition. The survey was conducted among adult women before the menopause and older than 30 years based on the data of the National Health and Nutrition Examination Survey carried out in the 4th term (2008-2009) and 5th term (2010-2011) and we would like to provide the research results for the establishment of recommendations or guidelines for the treatment of adult women before the menopause with regard to the impact factors on the bone mineral density and for the development of health education materials for the accurate measurement of bone mineral density of young women in order to prevent the postmenopausal osteoporosis. With respect to the general features of adult women before the menopause, the bone mineral density was higher in the entire femur at age 40-44, femoral neck at 35-39, in high-school education level, in the earlier menarche group, without smoking experiences, with regular walking time and exercise frequency and with the habits of eating no hamburger or pizza. With regard to the body composition, the bone mineral density was higher in obesity and lower in underweight cases, higher among people with abdominal obesity and weight control experiences. In terms of total body fat ratio, total amount of fat and muscle, the bone mineral density got gradually increased from the 1st quarter (Q1) to the 4th quarter(Q4). The obesity, disease, total amount of fat and muscle were shown to be significantly related with the bone mineral density in this research and it is required for young women to keep the adequate weight and the normal BMI in order to increase the bone mineral density. For the prevention of osteoporosis, it is advised to keep the right habits including regular exercise and no smoking discipline from the growing period and achieve the maximum bone mass thru the control of proper weight from a young age.