• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.107-116
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• 1998

Based on the differential growth response to exogenous gibberellic acid ($GA_{3}$) between semi-dwarf wheat(Triticum aestivum) and wild oat(Avena fatua), we examined the possibility of improving the selective performance of several herbicides by $GA_{3}$ application and the physiological background of $GA_{3}$-induced increase in herbicidal activity. Growth of wild oat was 4 to 5 times higher than that of wheat by $GA_{3}$ treatment. Pretreatment of wild oat seed with 300 ppm $GA_{3}$ increased the herbicidal activities of trifluralin and isoproturon by soil-surface application, but not of alachor and metsulfuron-methyl. $GA_{3}$ applied simultaneously with post-emergence herbicides resulted in a significant or moderate improvement of the efficacy of such herbicides as tralkoxydim, fenoxaprop-ethyl, metsulfuron-methyl, metribuzine and isoproturon, but not in the mixtures of oxyfluorfen or paraquat with $GA_{3}$. In the sequencial treatment of tralkoxydim and $GA_{3}$ at interval of one-day, $GA_{3}$ applied prior to tralkoxydim significantly increased a chlorosis and desiccation of leaf without affecting the growth inhibition by tralkoxydim. Tralkoxydim followed by $GA_{3}$ application had lower herbicidal activity than that of $GA_{3}$ followed by tralkoxydim treatment. Electrolyte leakage response of $GA_{3}$-pretreated or $GA_{3}$-untreated wild oat leaf against several compounds inducing membrane. peroxidation was compared. Differencial responses were observed in oxyfluorfen and isoproturon treatments with an increased electrolyte leakage in $GA_{3}$-pretreated tissue, but not in paraquat and rose bengal treatments. These results suggest that $GA_{3}$-induced increase in herbicidal activity is likely to be dependent on a herbicide type and may be due to activation of a metabolic ability related with herbicidal reponse as well as an increase in the herbicide absorbtion and translocation, rather than due to membrane and cell wall extention induced by $GA_{3}$, which in turn makes the herbicides easily enter.

• Korean Journal of Ichthyology
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• v.2 no.1
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• pp.53-62
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• 1990

Morphological development from egg to juvenile stages of the trident goby, Tridentigertrigonocephalu5 were observed in the laboratory at Pusan, Korea. The ripe eggs were spherical in shape, measuring 0.49-0.62 mm in diameter. The eggs became ellipsoid shape after the insemination and measured about 1.40-1.58 mm on the long axis. Hatching began about 158 hours after insemination at water temperature of $20.5-24^{\circ}C$. The newly hatched larvae were 2.88-3.14 mm in total length(TL), with 27-28(10+ 17-18) myomeres. Many melanophore and guanophores are distributed on eye cups, gas bladder, optic vesicle, intestine and the caudal region. Three days after hatching the yolk and oil-globule was completely absorbed and the larvae attained a total length 3.26-3.62 mm. The larvae swam actively in the aquarium and fed on the rotifer. Ten days after hatching, the larvae averaged 5.20 mm in TL and the caudal notochord flexed at $45^{\circ}$. Twenty days after hatching, the larvae averaged 7.47 mm in TL and rudimental anal, second dorsal, caudal and pectoral fins were formed. The larvae attained 12.05-12.65 mm in TL thirty five days after hatching and are found to transit the bottom-life, and first dorsal and ventral fins are completely formed. The larvae reached the juvenile stage at 45-50 days after hatching and attained 15.85-16.95 mm in TL, and all scales appeared on the body.

• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.1-10
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• 1991

Spawning behavior and development of eggs and larvae of Mugilogobius abei were observed in the laboratory at Pusan, Korea. The adult male of Mugilogobius abei was observed making nest-like spawning-bed to lay eggs and showing territorial and courtship behaviors. The eggs were transparent and spherical in shape, measuring 0.40~0.50 mm in diameter. They have a bundle of adhesive filaments at their basal end and a cluster of small oil globules. The eggs became ellipsoid shape after the insemination and measured about 0.93~0.96 mm on the long axis. Hatching began about 110 hours after fertilization at water temperature of $24.5{\sim}25.5^{\circ}C$. The newly hatched larvae were 2.04~2.10 mm in total length, with 24~25(8~9+16) myomeres. Many melanophore and guanophore are distributed on eye cups, gas bladder, optic vesicle and the caudal region. Four days after hatching the yolk and oil-globule were completely absorbed and the larvae attained a total length 2.20~2.35 mm. The larvae swam actively in the aquarium and start to practice feeding on the rotifer. Twelve days after hatching, the larvae averaged 3.20 mm in TL and the caudal notochord flex at $45^{\circ}$. Rudimental second dorsal, anal, caudal and ventral fins are also formed. The larvae attained 10.40~10.80 mm in TL, 35 days after hatching, are found to start the bottom-life after having completely formed first dorsal and ventral fins. The larvae reached the juvenile stage at 50~60 days after hatching and attained 15.37~20.25 mm in TL. At this period all scales appeared on the body.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.413-425
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• 2017

This manuscript describes the relationship between climate change and forest growth, forest species, carbon stocks, and tree mortality. 1) In the aspect of forest growth, the growth of major coniferous species, including Pinus densiflora, had a negative correlation with temperature. On the other hand, major deciduous oak species, including Quercus variabilis and Quercus mongolica, had a positive correlation with temperature. 2) When considered in the aspect of the forest species distribution, various models commonly showed a decrease in the distribution of coniferous species and an increase in oak species due to climate change in the medium to long term. 3) From the carbon stock perspective, there was a difference in the estimation according to the status of forest management. Most of Korean forests will mature to become over-matured forest after year 2030 and are estimated to produce approximately 410 million ton forest biomass until 2090 with the current cutting regulations for sustainable forest management announced by the Korean Forest Service. 4) In the forest mortality, the mortality rate of the major coniferous species showed a clear tendency to increase higher temperatures while it decreased for the oak species with no verification of statistical significance. Moreover, the mortality of the subalpine coniferous species was projected to progress rapidly. considering the overall impacts described above, there should be a management strategy for coniferous species that are relatively vulnerable to climate change. Moreover, a sustainable forest plan in the aspect of ecosystem services, carbon sequestration and storage, which is linked to global issues such as Sustainable Development Goals, ecosystem services and negative emission.

• Korean Journal of Environmental Agriculture
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• v.19 no.4
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• pp.314-318
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• 2000

To compare heavy metal phytoavailability in paddy soils near five abandoned mining areas, 4 different soil extractants such as 0.1M-HCl, $0.1M-HNO_3$, 0.05M-EDTA, and 0.005M-DTPA were used. Total acid digestion method $(H_2SO_4:HClO_4:HNO_3)$ was also employed to analyze heavy metal content in 30 paddy soils and brown rice. The rates of extracted heavy metal to total content were in the range of $12.1{\sim}39.1%$ for Cd, $20.5{\sim}45.5%$ for Cu, $10.6{\sim}30.7%$ for Pb, and $6.7{\sim}13.0%$ for Zn. 0.1M-HCl and $0.1M-HNO_3$ extractable both Cu and Pb were relatively less extracted at the high soil pH and extractable calcium site(Mine D) whereas 0.05M-EDTA and 0.005M-DTPA extractable Pb were strongly extracted at the same soils. In case of Cd, Cu, and Zn in soil, 4 types of extractable heavy metals and total content were highly correlated with each other. However, there were positive correlations between 0.1 M-HCl and $0.1M-HNO_3$ extractable Pb as well as between 0.05M-EDTA and 0.005M-DTPA extractable Pb, which were relatively similar extractants in chemical properties. The rates of heavy metals in brown rice to total contents in soils were in the order Zn>Cd>Cu>Pb. Specially, the rate of Cd, Pb, and Zn were lower at the highest level of soil pH and Ex. Ca. Both Cd and Zn in brown rice were positively correlated with those of all soil extractants. It was estimated that the solubility following to the plant uptake of Cd and Zn were higher than those of Cu and Pb considering relationships between all kinds of heavy metal contents in soil and those in brown rice.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.224-230
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• 2013

BACKGROUND: Perchlorate(${ClO_4}^-$) is an anion that is extremely water-soluble and environmentally stable. It mostly exists in the form of sodium perchlorate, ammonium perchlorate and potassium perchlorate which are used in rocket fuels, propellants, ignitable sources, air bag inflation systems and explosives. Perchlorate can be taken into the thyroid glands and interfere with iodide uptake. The determination of perchlorate in agricultural products is important due to its potential health impact on humans. The objective of this study was to determine the perchlorate concentrations in the samples of various agricultural products and soils. METHODS AND RESULTS: In this study, samples of cereal(Rice, Barley, Corn, Bean), vegetable(Spinach, Lettuce, Sesame, Chives, Chili, Pumpkin, Tomato), fruit(Apple, Pear, Tangerine, Grape) were analyzed for perchlorate contents. Perchlorate concentrations were analyzed by liquid chromatography-tandem mass spectrometry. The results showed that agricultural products respectively contained perchlorate concentrations in the range of : cereals N.D.~$7.46{\mu}g/kg$, vegetables $0.52{\sim}23.06{\mu}g/kg$, fruits $0.19{\sim}2.66{\mu}g/kg$. Bioconcentration factor was in the order of : vegetables > cereals > fruits. Bioconcentration factor was highest follwed by Sesame 37.88, Corn 21.51, Spinach 10.57, Tangerine 4.39, Chives 2.89 and Lettuce 1.90. The recoveries of perchlorate from spiked agricultural products and soils ranged from 87.72~111.26% and 102.09~111.23%. CONCLUSION(S): The health risk assessment results obtained in this study are lower than the RfD(Reference Dose, 0.0007 mg/kg/body weight/day) value as suggested by the Integrated Risk Information System(US IRIS). Our results indicate that, people currently exposed to perchlorate from agricultural products consumption are considered as safe.

• Development and Reproduction
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• v.11 no.2
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• pp.127-135
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• 2007

In order to monitor the developmental features of embryos, larvae, and juveniles of Konoshiro Gizzard Shad Konosirus punctatus, the fertilized eggs were gotton using artificial insemination. Konosirus punctatus were caught in Mankyung-myeon, Kimjae, Jeollabuk-do at June of 2004, and experiments were carried out in Ichthyology laboratory in Chonnam National University. Konosirus punctatus spawned draft egg from March to June. The fertilized eggs were cultured in $19.0{\sim}23.0^{\circ}C$(mean, $21.2^{\circ}C)$. The eggs had spherical shape and the diameter is $1.14{\sim}1.34\;mm$(mean, 1.21 mm). The lens began to appear from 35 hr 53 min after fertilization. At the moment, the movement of larvae was more active, and the tail was separated completely from yolk, the heart had forms, and melanophore appeared. Hatching was observed from 37 hr 10 min after fertilization. The total length of the hatched larvae was $4.26{\sim}5.30\;mm$(mean, 4.96 mm), but the mouth and anus were not opened at the time when the larva had yolk sack, and had $22{\sim}27$ myometium, and the anus located just abdominal front of the tail fin, and melanophore accumulated in the eye. Post-larvae used yolk completely after 2 day of hatching, and the total length was $4.96{\sim}5.74\;mm$(mean, 5.24 mm). From 16 days after hatching, the tail had curved tail end, and appeared the stems for pectoral, dorsal, and caudal fins. At 53 days after hatching, the total length of post-larvae was $27.11{\sim}34.09\;mm$(mean, 30.11 mm), and the frontal part of head developed like an adult one. At this time, fins and body are transferred to those of adult Konosirus punctatus. Fishes have a different shape and location of melanophore even in the same family. This research was tried to elucidate the early developmental features of Konosirus punctatus, together with species-specific pattern of melanophore.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.100-103
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• 2010

Purpose: $^{18}F$-FDG wholebody PET is to evaluate the tumor using glucose metabolism. The blood glucose level is important factor that affects on a result of examination. High glucose levels may interfere with tumor targeting due to competitive inhibition of FDG uptake by D-glucose. The blood glucose level measurement test strips used in the blood glucose measurement are classified into the capillary blood measurement test strips and general purpose measurement test strips that can measure the venous blood and capillary blood altogether depends on cases. The purpose of the study was to compare the blood glucose measurements between simultaneously obtained capillary and venous blood samples using the capillary blood measurement test strips, general purpose measurement test strips. Materials and Methods: A total of 46 subjects (32 males, 14 females) with a mean age of $57.3{\pm}12.3$ years were enrolled. The blood glucose estimation was performed with a Optium Xceed Glucometer (Abbott). Simultaneous capillary and venous blood samples were obtained from each subject. The blood glucose levels were measured using the capillary blood measurement test strips and general purpose measurement test strips. The capillary and venous measurements were compared using a pared t-test. Results: The mean capillary and venous glucose values using the general purpose measurement test strips were $95.2{\pm}12.4$ mg/dL and $104.1{\pm}14.4$ mg/dL, giving a statistically significant difference (p<0.001) between the mean values for the capillary and venous glucose samples (9.0 mg/dL; 95% confidence interval (CI) -11.2 to -6.7). The mean capillary and venous glucose values using the capillary blood measurement test strips were $91.5{\pm}13.6$ mg/dL and $108.6{\pm}16.2$ mg/dL, giving a statistically significant difference (p<0.001) between the mean values for the capillary and venous glucose samples (16.6 mg/dL; 95% CI -20.2 to -13.0). Conclusion: When measuring the blood glucose level before $^{18}F$-FDG PET examination, since the incorrect blood glucose level can be measured, it should note to measure the blood glucose level of the venous blood by the capillary blood measurement test strips. Therefore the measurement variation can be reduced to fulfill the standardized measurement procedure with the suitable measurement test strips, the preparation of the PET examination will be able to be clearly confirmed. In addition, the standardized procedure of the following measurement on the area which is same at all times the blood area in the blood glucose measurement among a capillary or a vein will be needed.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.124-130
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• 2006

Rice plant extracts of brown planthopper (BPH) resistant rice varieties, Jangseongbyeo (JSB) and Hwacheongbyeo (HCB) at different growth stages (seedling, tillering, heading and ripening) were sequentially fractioned using hexane, ethyl ether, ethyl acetate, butanol, and distilled water. The extracts were applied to BPH susceptible rice variety, Dongjjnbyeo (DJB), to investigate the insecticidal and repellent effects against BPH. BPH insecticidal effects were not clearly observed with almost all of the extract fractions obtained from both JSB and HCB varieties for 12 h, whereas the ethyl ether and hexane extract fractions showed about 10 to 30% of BPH mortality in 24 to 48 h of application periods. An effective BPH repellent activity was found with the applications of ethyl ether extract fractions obtained from JSB variety. The extract fractions obtained from HCB variety did not show any different repellence among the various fractions. The BPH repellent effects of the extract fractions obtained at different growth stages of either JSB or HCB varieties did not show any correlations. The effect of ethyl ether fraction on BPH repellent was continually increased by 30 h after treatment and thereafter decreased. In addition, the first sub-fraction separated by a flash column chromatography eluted with chloroform:methanol (9:1, v/v) from the BPH effective ethyl ether faction in JSB variety might be meaningful to repel BPH from BPH susceptible target rice plants. The results indicated that the ethyl ether fraction obtained from JSB was higher in repellent activity than in insecticidal activity, and suggesting that there might be specific substance(s) in the first sub-fraction (sF1) of the ethyl ether fraction in JSB that could provide repellent activity against BPH.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.93-103
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• 2016

A simultaneous analytical method was developed for the determination of isoxaflutole and metabolite (diketonitrile) in agricultural commodities. Samples were extracted with 0.1% acetic acid in water/acetonitrile (2/8, v/v) and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2 by 1 N hydrochloric acid. The analytes were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive-ion mode using multiple reaction monitoring (MRM). Matrix matched calibration curves were linear over the calibration ranges ($0.02-2.0{\mu}g/mL$) for all the analytes into blank extract with $r^2$ > 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. The recoveries were ranged between 72.9 to 107.3%, with relative standard deviations (RSDs) less than 10% for all analytes. All values were consistent with the criteria ranges requested in the Codex guideline (CAC/GL40, 2003). Furthermore, inter-laboratory study was conducted to validate the method. The proposed analytical method was accurate, effective, and sensitive for isoxaflutole and diketonitrile determination in agricultural commodities.