• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.397-403
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• 2022

Smilax sieboldii is one of the Smilax species. A number of Smilax plants have long been used in traditional medicine in the tropics and subtropics worldwide. Repeated dose oral toxicity test is an essential experiment for toxicity evaluation before efficacy evaluation. The purpose of this study is to evaluate toxicity and the no-observed adverse effect level (NOAEL) using oral administration of Smilax sieboldii extract (SSE) in male and female ICR mice for 4 weeks. SSE was orally administered daily for 4 weeks at a dose of 500, 1000, and 2000 mg/kg/day (MPK). There were no significant differences in mortalities, clinical signs, body weight changes, food intake, hematological analysis, serum clinical chemistry test and relative organ weights in all animals administrated with SSE. The results obtained in this study suggest that SSE did not show any toxic effect in ICR mice and the NOAEL of SSE was regarded as over 2000 MPK.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.843-853
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• 2021

The objectives of this paper were to simply estimate soil loss levels as caused by wind in reclaimed tidal flat land (RTFL) and the threshold wind velocity in the RTFL. For this experiment, RTFL located at Haenam Bay was selected and a total of 150 soil samples were collected at the Ap horizon from the five soil series. The particle distribution curves, including the limit of the non-erodible particle size (D > 0.84 mm) for each Ap horizon soil, show that the proportions of non-erodible particle sizes that exceeded 0.84 mm were 4.3% (Taehan, TH), 8.9% (Geangpo, GP), 0.5% (Bokchun, BC), 1.6% (Poseung, PS) and 1.4% (Junbook, JB), indicating that the amount of non-erodible soil particles increased with an increase in the sand content. The average monthly, daily and instantaneous wind velocities were higher than the threshold friction velocity (TFV) calculated according to the dynamic velocity (V_d) by Bagnold, while the average monthly wind velocity was lower than those of the TFV suggested by the revised wind erosion equation (RWEQ) and wind erosion prediction system (WEPS). The susceptible proportions of erodible soil particles from the Ap horizon soil samples from each soil series could be significantly influenced by the proportion of sand particles between 0.025 and 0.5 mm (or 0.84 mm) in diameter regardless of the threshold wind velocity. Thus, further investigations are needed to estimate more precisely soil erosion in RTFL, which shows various soil characteristics, as these estimations of soil loss in the five soil series were obtained only when considering wind velocities and soil textures.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.685-691
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• 2020

Standard values for fetal bio index measurements should be applied differently depending on the past present and general characteristics of the target population. Therefore, we tried to predict the number of gestational week(GA) and analyze the differences by country based on the measurements of Korean fetal bio index. 480 fetal bio index measurements between 15~38 weeks of pregnancy using ultrasound were compared retrospectively with USA ad Japanese data. One Way ANOVA was used for the analysis of differences by country, and quadratic regression model was designed to predict the GA of fetal bio index in order to predict the standard pregnancy number of Korean fetuses(p<0.005). Mean difference in the 95% confidence interval is BPD was Korea and USA 0.17, Korea and Japan 0.11, AC was Korea and USA -0.35, Korea and Japan 0.42, FL was Korea and USA -0.18, Korea and Japan 0.14. Therefore, fetal bio index for GA predict is considered to be the standard of the fetal growth assessment by applying the country specific standard in consideration of differences between races.

• Korean Journal of Environmental Agriculture
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• v.26 no.4
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• pp.319-324
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• 2007

This study was conducted to evaluate the persistence of DNA in the transgenic chili pepper resistant to cucumber mosaic virus (CMV) in the field condition. We analyzed the persistence of genes in the leaf samples obtained from two field conditions, below and above soil. Transgenic and non-transgenic leaf tissues were buried in the soil at a depth of 10 cm or placed on the soil surface. Qualitative and quantitative PCR analysis showed that the amount of transferred genes from the transgenic peppers below and above soil was dropped to 28.3-42.7% one month after buried and it was rapidly reduced to 0.9-3.3% after two months. The transgenes were not detected three to four month after buried. In addition, DNA of the leaves placed below soil decomposed about 8%more than those on soil surface. The gene transfer from decomposing leaves of the transgenic pepper to soil was investigated by PCR analysis with the soil attached to the samples. The PCR result indicated that the gene transfer from the transgenic pepper to soil was not occurred.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.235-243
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• 2012

Objectives: The purpose of this study is the work environment management method through risk assessment and investigation of the work place that deals with Ammonium nitrate, based on information in and outside the country. Methods: This study suggests method of work environment management through risk assessment and investigation of the work place that deals with Ammonium nitrate, and finds out cases of Ammonium nitrate causing hazard, danger and health risk, based on literature investigation. Results: Rats exposed repeatedly to $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin) which cause high level of skin irritation, reported 1 $mg/m^3$ of NOAEL, while LOAEL was less than 100 mg/kg for the rats orally administered with the $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin), for 13 weeks. Domestically 31,640 ton/y of ammonium nitrate has been used in 22 workplace and the result of workplace assessment was 0.0171-0.9983 $mg/m^3$. ADD was 8.77-59.63 ${\mu}g/kg-day$ according to the exposure scenario. In other words the result of the risk assessment goes beyond the 'standard 1'. Conclusions: Ammonium nitrate creates a high level of irritation and toxicity when coming in breathe it or contact with skin, and is classified as category3 of GHS and specific target organ toxicant (irritating respiratory system). Exposure level at work places needs to be maintained under $1mg/m^3$, to prevent workers from being damaged.

• Environmental Analysis Health and Toxicology
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• v.28
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• pp.17.1-17.3
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• 2013

The fact that hazardous metals do not bio-degrade or bio-deteriorate translates to long-lasting environmental effects. In the context of evidently rapid global industrialization, this ought to warrant serious caution, particularly in developing countries. In the Republic of Fiji, a developing country in the South Pacific, several different environmental studies over the past 20 years have shown levels of lead, copper, zinc and iron in sediments of the Suva Harbor to be 6.2, 3.9, 3.3 and 2.1 times more than the accepted background reference levels, respectively. High levels of mercury have also been reported in lagoon shellfish. These data inevitably warrant thorough assessment of the waste practices of industries located upstream from the estuaries, but in addition, an exposure and health impact assessment has never been conducted. Relevant government departments are duty-bound, at least to the general public that reside in and consume seafood from the vicinities of the Suva Harbor, to investigate possible human effects of the elevated hazardous metal concentrations found consistently in 20 years of surface sediment analysis. Furthermore, pollution of the intermediate food web with hazardous metals should be investigated, regardless of whether human effects are eventually confirmed present or not.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.33-45
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• 1997

Nowadays, the environmental conservation has become a hot issue. Also the sustainable city issue is recognized as one of the most important tasks to be solved urgently for urban development. Therefore, the current indicator for sustainable city has been analyzed only as a segment of the environmental indicator which is one kind of branch of social indicator. However, considering the degree of pollution and heightened concern, it is time to develop a new and improved framework for the analysis of the sustainable city indicator. This study aims for the development of sustainable city indicator and the examination of practical method for the use of them. Urban sustainable city indicators are based on the "Pressure-State-Response (PSR) framework" which has been adopted by Organization for Economic Cooperation and Development (OECD). The indicators suggested in this study is composed of the following categories: 1. Indicators of natural environment itself, such as land structure (available land use index etc.), bio-species (bio-diversity index etc.), environment resources (water quantity index etc.) 2. Indicators of relationship between man and environment, such as sustainability of using material (recycle of water index etc.), pressure size (pressure index on air etc.), effort of prevention (environmental basic facility index, etc.) 3. Indicators of environmental state, such as landscape and culture (historical & cultural index etc.), environmental pollution (air pollution index etc.) A sustainable city environment is necessary and obtainable, yet its realization seems to be difficult. The urban pollution problems have become more serious than ever before thus requiring much interest. Therefore, this kind of study is meaningful for the establishment of policy objective, and the development and management environmentally sound and sustainable cities.

• Development and Reproduction
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• v.22 no.1
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• pp.111-117
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• 2018

The objective of this study was to determine the mitotic intervals (${\tau}_0$) of two consecutive cell divisions and synchronous embryonic cleavage in grass puffer, Takifugu niphobles at different water temperatures (18, 20, 22, and $24^{\circ}C$). The color of the fertilized egg was light yellowish. The egg type was demersal and unadhesive. Egg weight was $0.09{\pm}0.002mg$. The sizes of unfertilized eggs were smaller than fertilized eggs in major axis and minor axis at $20^{\circ}C$ (p<0.05). The size of the fertilized egg of $18^{\circ}C$ water temperature group at the blastodisc stage was the smallest (p<0.05), but no significant differences were observed in the other water temperatures group except $18^{\circ}C$ water temperature group (p>0.05). The first cleavage stages at 18, 20, 22, and $24^{\circ}C$ were at 75, 90, 105, and 120 mins, respectively. As water temperature was increased, embryonic development and formation time of the first cleavage furrow were accelerated. There were negative correlation between ${\tau}_0$ and water temperature for grass puffer (Y=-1.225X+70.05, $R^2=0.988$, n=10, where Y was ${\tau}_0$ and X was temperature). This study confirmed that successful hatching of grass puffer was related to water temperature. Chromosome manipulation will be helpful for this species using cleavage frequency and ${\tau}_0$.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.1
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• pp.79-89
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• 2022

Soil moisture is significantly related to crop growth and plays an important role in irrigation management. To predict soil moisture, various process-based model has been developed and used in the world. Various models (Land surface model) may have different performance depending on the model parameters and structures that causes the different model output for the same modeling condition. In this study, the three land surface models (Noah Land Surface Model, Soil Water Atmosphere Plant, Community Land Model) were used to compare the model performance (soil moisture prediction) and develop the multi-model simulation. At first, the genetic algorithm was used to estimate the optimal soil parameters for each model, and the parameters were used to predict soil moisture in the study area. Then, we used the multi-model approach based on Bayesian model averaging (BMA). The results derived from this approach showed a better match to the measurements than the results from the original single land surface model. In addition, identifying the strengths and weaknesses of the single model and utilizing multi-model methods can help to increase the accuracy of soil moisture prediction.

• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.43-53
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• 2024

This research undertook the assessment of six types of silicone sealants prepared. Their resistance to fungi was evaluated according to ASTM G 21, LH specification(LHCS 41 40 12), and the newly instituted KS F ISO 21265 test methods. The findings showed that KS F ISO 21265 test method exhibited the superior discriminative capability in assessing fungal resistance when compared to ASTM G 21 and LH specification(LHCS 41 40 12) test methods. Additionally, it was confirmed that oxime curing sealants demonstrated higher fungal resistance than alkoxy curing sealants. Furthermore, The introduction of a condition to assess fungal resistance after 4 weeks of immersion at 50℃ in KS F ISO 21265 is expected to enable long-term fungal resistance evaluation of sealants.