• Korean Journal of Environmental Agriculture
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• v.21 no.1
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• pp.57-68
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• 2002

In order to elucidate the effect of phenobarbital sodium (PB) and 3-methylcholanthrene (3-MC) on metabolism of insecticide carbofuran in rat. Carbofuran metabolites and its formation rates were determined when orally administered $^{14}C$-carbofuran alone and its combination with PB or 3-MC to rat. $^{14}C$-carbofuran administered orally, alone or in combination with PB or 3-MC, was secreted rapidly within 48 hrs. That is, 79.9 to 81.1% of the original radioactivity was secreted into the urine and 5.7 to 6.5% into the feces. The secretion rate was faster in the combined administration than that in carbofuran alone. Metabolites of carbofuran in main organs, urine, feces and blood of rat were largely 3-hydroxycarbofuran, 3-ketocarbofuran, 3-hydroxycarbofuran phenol, 3-ketocarbofuran phenol, and carbofuran phenol, the major ones being 3-hydroxycarbofuran and 3-ketocarbofuran, respectively, in all administrations of carbofuran alone, carbofuran+PB and carbofuran+3-MC. In addition, formation rate of the two major metabolites detected in the urine was 17.4% and 12.8%, respectively, when carbofuran alone was administered. Meanwhile, when carbofuran was administered with PB or 3-MC, they were 8.6% and 23.5, repectively. These results indicate that the oral administration of PB or 3-MC can reduce carbofuran toxicity by fastening and stimulating the carbofuran metabolism in rat.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.25-30
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• 1997

Absorption, distribution, metabolism and excretion of $^{14}C-carbofuran$(2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamte) were studied in carp(Cyprinus carpio L.) after the treatment of carbofuran at the dose level of 43 parts per billion. Maximum radioactivities in tissues(liver, kidney, gut, gall bladder) and blood of carp were shown 12hrs after the treatment of $^{14}C-carbofuran$. Carbofuran was metabolized to 3-hydroxycarbofuran and 3-ketocarbofuran in liver and kindney of carp, and the major metabolite was 3-hydroxycarbofuran. Most radioactivity absorbed into the carp tissues was eliminated 3hrs after transfer of the carp to fresh water. The excretory metabolites were 3-ketocarbofuran(32.3%), 3-hydroxycarbofuran(52.8%) and an unknown metabolite(2.6%) during the period of 3hrs of the excretory experiment.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.37-46
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• 1999

In order to ascertain the safety of the systemic insecticide carbofuran-treated crops, samples of garlic, peanut and potato were collected randomly from markets located in the main producing areas and analyzed for the residue of carbofuran and its main metabolite, 3-hydroxycarbofuran. The in vitro metabolism of carbofuran in phosphate buffer extracts of the crops was investigated. Two (M-12 and M-16) out of 20 mature garlic samples contained 0.13 and 0.07 mg/kg of carbohran, respectively, showing a detection incidence of 10%. The residue levels were less than the maximum residue limit (0.5 ppm) set by Korean Food and Drug Administration. Only one sample of mature garlic (M-12) out of 20 contained 0.13 mg/kg of 3-hydroxycarbofuran. The residues of carbofuran and 3-hydroxycarbofuran in the immature garlic, peanut and potato samples were less than the detection limits, 0.02 mg/kg for carbofuran and 0.06 mg/kg for 3-hydroxycarbofuran. The application of carbofuran to the fields of garlic, peanut and potato would be safe, considering that the estimated maximum acceptable daily intake of carbofuran from garlic was 0.0013 mg which is 0.24% of the maximum acceptable daily intake (0.55 mg). Carbofuran was hydrolyzed in vitro mainly to carbofuran phenol (m/z 164) in the respective phosphate buffer extracts of the three crops in contrast to the major oxidative metabolism in situ. The amount of the metabolite increased with the incubation time.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.7-16
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• 1987

A study was undertaken to investigate the absorption, translocation and metabolism of carbofuran in rice paddies. Ring-3-$^{14}C-carbofuran$ applied onto the paddy soil surface was rapidly absorbed and translocated into rice plants. Within 2 days after treatment, it was observed that carbofuran reached shoot tips and accumulated. More than 15% of total radioactivity was recovered in rice plant from 3 to 20 days after treatment. In organic soluble fraction of rice plant extract, 3-hydroxycarbofuran was the major metabolite recording 43% and 4% of total organic soluble radioactivity in shoot and root at 20 days respectively. 3-Ketocarbofuran and phenolic metabolites including carbofuran phenol, 3-hydroxycarbofuran phenol and 3-ketocarbofuran phenol were also detected in the organic soluble fractions. Some glycosidic conjugates of carbofuran metabolites were found in water soluble fraction of rice plant extract and 3-hydroxycarbofuran was the most abundant aglycone. Radioactivity in paddy soil was rapidly decreased until 3 days after treatment and then maintained almost constant level. A significant portion (42∼56 %) of the total radioactivity remained in soil as nonextractable residue from 5 to 20 days after treatment. The nonextractable radioactivity was mainly located in soil organic matter distributing in humin, fulvic acid and humic acid fractions with the decreasing order. Evolution of $^{14}CO_2$ from ring cleavage of $3-^{14}C-carbofuran$ was negligible recording only 1.8% of total radioactivity during 20 days after treatment.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.29-38
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• 1998

In order to elucidate the effect of phenobarbital sodium(PB) and 3-methylcholanthrene(3-MC) on metabolism in vitro and toxicity of $^{14}C$-carbofuran in rat, they were administered by the chemicals, alone or in combination, and their survival ratios and metabolites were investigated. The $LD_{50}$(96 hrs) value of carbofuran to rats was 6.9 mg/kg. The toxicities of the major metabolites were in the decreasing order of 3-hydroxycarbofuran, 3-ketocarbofuran, 3-hydroxycarbofuran phenol and were much lower than that of the parent compound. When the rats were orally administered by the dose of carbofuran alone, 8.4 mg/kg, the survival ratio was 0%, whereas that was raised up to $60{\sim}80%$ with 20 mg/kg of PB or 3-MC, and 100% with 60 mg/kg of PB or 3-MC. Their metabolism in vitro occurred in the microsomal fraction. In case of carbofuran alone, the major metabolite was 3-hydroxycarbofuran. When carbofuran with PB or 3-MC, on the other hand, was treated, it was 3-ketocarbofuran. In addition, when the co-factor(NADP+G-6-P+G-6-P-DG) was added to the microsomal fraction(phase I system), and a mixture of NADPH+GSH to the 105,000g supernatant(phase II system) taken by carbofuran alone, each metabolites were produced by the maximum levels, respectively. In case of the carbofuran treatment with PB or 3-MC, the microsomal fraction of phase I system produced the maximum levels of metabolites, as in the treatment of carbofuran alone, whereas the 105,000g supernatant supplemented with the co-factor NADPH+FAD(phase II system) was brought about the maximum production of metabolites. The ratio of the formation of metabolites was 2 to 3 times higher in the combined treatment of carbofuran with PB or 3-MC than in the treatment of carbofuran alone.

• Korean Journal of Environmental Agriculture
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• v.5 no.2
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• pp.85-94
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• 1986

To study fate of carbofuran in paddy system, C-14 labelled carbofuran was applied to paddy water containing rice seedlings and time course study was made on the distribution, metabolism and chemical transformation of the systemic insecticide. Carbofuran was readily absorbed by plant root and translocated to shoots where most of the radioactivities were confined to leaf tips. The fact that gradual increases in radioactivities of both aqueous phase extracts and non-extractable fractions of plants (shoots and root) increased with incubation is taken as an evidence that reactions (phase I and II) proceed in rice plants. Carbofuran and its five metabolites were all detected by TLC in organic phase extracts of paddy plants or soil. Evidence was put forward that carbofuran and its five metabolites were all identified as aglycones of conjugates. 7-benzofuranol and 3-hydroxycarbofuran were the most abundant aglycones. Soil microbes appears to have little effects on the metabolism of carbofuran. They increased radioactivity of non-extractable fraction and reduced that of organic phase extracts of paddy soil.

• Korean Journal of Environmental Agriculture
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• v.3 no.2
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• pp.9-15
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• 1984

Experiments were carried out with purified technical grade and two types of impregnated and sand-coated granules of carbofuran, in order to investigate the release patterns in water and the persistence of this chemical in soils. The results obtained are summarized as follows: 1) As regards to release velocity in water, impregnated granule was found to be faster than sand-coated granule. The time to reach maximum concentrations of carbofuran in water from technical carbofuran, impregnated granule and sand-coated granule was 0.5, 3 and 5 days, respectively. 2) Degradation rate of carbofuran in soils decreased in the order of technical carbofuran, impregnated granule, sand-coated granule regardless of soil types and application rates. Degradation of carbofuran in flooded soil was faster than in non-flooded soil. Soil flooding appeared to be the main factor in promoting the degradation of carbofuran in the soil. 3) When carbofuran was fortified in soils in the form of technical carbofuran, impregnated granule or sand-coated granule, the persistencies of two terminal residues of carbofuran, that is, 3-hydroxy carbofuran and 3-keto carbofuran decreased in the order of sand-coated granule, impregnated granule and technical form.

• Journal of KIISE:Software and Applications
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• v.27 no.8
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• pp.864-876
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• 2000

This paper proposes a new scene boundary detection scheme for the MPEG System stream using MPEG Audio information and proves its usefulness by extensive experiments. A scene boundary has a characteristic that the audio as well as video information are changed rapidly. This paper first classifies this scene boundary into three cases ; Radical, Gradual, Micro Changes, with respect to the audio changes. The Radical change has a large-scale changing of decibel value and pitch value at a scene boundary, the Gradual change shows the long-time transition of decibel and pitch values from max to min or vice versa, and the Micro change displays a some change of pitch or frequency distribution without decibel changes. Upon this analysis, a new scene change detection algorithm detecting these three cases is proposed in which a progressive window with a time line is used to trace the changes in the audio information. Some experiments with various movies show that proposed algorithm could produce a high detection ratio for Radical change that is the most popular scene change in the movies, while producing a moderate detection ratio for Gradual and Micro changes. The proposed scene boundary detection scheme could be used to build a database for visual information like MPEG System stream.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.2
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• pp.135-149
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• 2000

Most of prior works on testing parallel programs have concentrated on how to guarantee the reproducibility by employing event traces exercised during executions of a program. Consequently, little work has been done to generate test cases, especially, from specifications produced from software development process. In this research work, we devise the techniques for deriving test cases automatically from the specifications written in Message Sequence Charts(MSCs) which are widely used in telecommunication areas and develop the testing environment for performing module testing of parallel programs with derived test cases. For deriving test cases from MSCs, we have to uncover the causality relations among events embedded implicitly in MSCs. For this, we devise the methods for adapting vector time stamping to MSCs, Then, valid event sequences, satisfying the causality relations, are generated and these are used as test cases. The generated test cases, written in TTCN, are translated into CHILL source codes, which interact with a target module to be tested and test the validity of behaviors of the module. Since the testing method developed in this research work extracts test cases from the MSC specifications produced front telecommunications software development process, it is not necessary to describe auxiliary specifications for testing. In audition adapting vector time stamping generates automatically the event sequences, the generated event sequences that are ones for whole system can be used for individual testing purpose.