• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.19-24
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• 2014

The purpose of the present study was to determine the priming effects of progesterone that affect the emergence of LH surge mode secretion by three different progesterone levels. In previous studies, we have shown that LH surge occurred in follicular levels of progesterone, whereas there was no surge mode secretion of LH and FSH in either the subluteal or luteal levels of progesterone. In this study, the hypothesis was that the priming effects of progesterone on the timing of the LH surge induced by exogenous estradiol are same between subluteal and luteal levels of progesterone. Long-term ovariectomized Shiba goats that had received implants of estradiol capsules (Day 0) and three different progesterone silastic packet inducing follicular, subluteal and luteal levels of progesterone were divided into three groups such as non-P, low-P and high-P group. Blood samples were collected daily throughout the experiment for the analysis of gonadal steroid hormone levels. On Day 7, all devices of progesterone packets were removed but estradiol capsules were maintained during the experiment, and blood samples were collected at 1 hr interval for 12 h from the time of progesterone removals to determine peripheral changes of estradiol and progesterone concentration. Then all animals were infused estradiol on the Day 7 after 13 h from the removals of progesterone devices with a peristaltic pump into jugular vein at a rate of 3 ${\mu}g/h$ for 36 h. For analysis of peripheral LH and estradiol concentration, blood samples were collected via another jugular vein at 2 h intervals for 52 h (from 4 h before the start of estradiol infusion to 48 h after the start of estradiol infusion). In all animals of the three groups treated with estradiol infusion, an LH surge was expressed but the peak time of LH surge was different. This time interval from estradiol infusion until the peak of LH surge was gradually and significantly extended by the different levels of progesterone treated before estradiol infusions in the three groups.

• Journal of Sericultural and Entomological Science
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• v.2
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• pp.49-61
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• 1962

The insect Diplosis mori Yokoyama is causing extensive destruction of mulberry trees in Korea with a resultant loss in silk production. This study was made to determine an effective method of control. Methods and Materials Used Preliminary studies were made to determine more exactly the life cycle of the insect. Based on this information, various control measures were tested, including the use of spray methods with BHC and control of larvae by tilling. Results Obtained 1. Life cycle studies (a) In the Suwon area, this-insect has 5 generations per year. The first starts in the later part of June and the final cycle ends in the later part of September. (b) The adult insects appear about 7: 00-8: 00 P.M. and live for 2-5 days. Females live in longer periods than the male. (c) Larvae lives inside the second and third stipules (A. B.) before mulberry leaf development. They cause extensive damage to the leaves at the point where they are attached to the stem. (d) Weather conditions considerably affect the life cycle. The pupa particularly are affected and not be able to change into the moth stage when there is a long period of no rain. (e) Larvae are large......0.3 to 2.0mm......and are milky-white immediately after hatching but turn to pinkish as the worm matures. The matured worm has a jumping ability up to 15-20cm. The worm burrows into the ground 1.5 to 3.0 cm before changing into the pupal stage. (f) The pupal stage usually lasts 7-8 days, in summer weather conditions and the pupa is surrounded with a coarse cocoon. (g) These insects, as a general rule, overwinter as pupae but sometimes as larvae. 2. Control measures (a) BHC dust applied on the ground seem most effective. It should be done 4-5 days after the worm has burrowed into the ground. For this control, it is recommended that 6kg of a 2% formation Tanbo(l0ares) be used. (b) For the effective spraying against the fly, it is recommended that a formulation of liquid BHC spray terials be used at the rate of 400-600 liters per Tanbo. (c) Tillage methods which provide a cover of soil 5cm or more in depth above infested areas will effect-maively prevent the emergence of the fly from the pupal stage. 3. Conclusions Methods of control against Diplosis mori Yokoyama can be tied more closely to the life cycle of the insect with more effective results. Further studies are needed to complete information on possible controls during or after hibernation. Economic studies on the cost of these control measures are also needed.

• Clinical and Experimental Pediatrics
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• v.49 no.7
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• pp.726-731
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• 2006

Purpose : We reported previously that intramuscular ketamine with adjunctive midazolam is more effective than ketamine alone in pediatric procedural sedation, but with limited satisfactory sedation by suboptimal ketamine dose. The optimal dose of intramuscular ketamine in children has never been studied in Korea. In this study, we investigated the effectiveness and adverse events of ketamine 4mg/kg with adjunctive midazolam in pediatric laceration repair. Methods : From Jan. 2005 to July 2005, we enrolled 60 children, aged 3 months-7 years, who needed laceration repair under sedation. After verbal consent from parents, patients were randomly assigned to KMA group(IM ketamine 4 mg/kg＋atropine 0.01 mg/kg＋intramuscular midazolam 0.05 mg/kg) or KA group(without midazolam). We compared both groups with the induction time, recovery time, total sedation time, efficacy of sedation, adverse effects, and the satisfaction score of treating physicians. Results : Potentially confounding variables, age, weight, injury site and anxiety score, were similar between groups. The induction time, recovery time and total sedation time were not different statistically. In KMA group, 90.9 percent of patients showed satisfactory sedation compared to 66.7 percent of KA group(P=0.02) and the occurrence rate of significant adverse effect was 0.0 percent and 37.0 percent respectively. Conclusion : We found adjunctive midazolam with ketamine doses of 4 mg/kg IM produced more effective, satisfactory sedation and less adverse effect than without midazolam in pediatric laceration repair. The emergence phenomenon(agitation during recovery) only occurred in 9 KA group patients. In spite of adverse effect, all patients recovered, were discharged and there were no reported delayed events.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.250-259
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• 2011

This study was conducted to assess the possibility of 5,8-dihydroxy-1,4-naphthoquinone (DHNQ) as a environmental friendly herbicide candidate. Foliar application of DHNQ showed excellent herbicidal effect to the 3 grasses and 5 broad-leaved weeds. Among them, Digitaria sanguinalis and Solanum nigrum were completely controlled by $250{\mu}g\;mL^{-1}$ of DHNQ with main symptoms of desiccation or burndown within 24 hours. Aeschynomene indica was also sensitive to DHNQ treatment. All of the eight weed species were controlled by 90~100% at a concentration of $1000{\mu}g\;mL^{-1}$. However, soil application of DHNQ to Digitaria sanguinalis did not show any herbicidal symptoms. DHNQ strongly inhibited KAPAS activities in vitro and the $IC_{50}$ was $4.4{\mu}M$. Cellular leakage from cucumber leaf squares treated with DHNQ increased depending on the concentrations increased from 6.25 to $100{\mu}M$ after 24 hours incubation with or without light. However, chlorophyll loss in cucumber leaf squares was negligible. Biotin supplements significantly rescued the inhibition of germination rate of Arabidopsis thaliana seeds previously inhibited by the DHNQ. According to above results, DHNQ is a good natural herbicide candidate having a new target KAPAS, which is involved in biotin biosynthesis pathway, with environmental friendly.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.291-299
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• 2010

Cyhalofop-butyl and penoxsulam, known for respective acetyl CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor, have been widely using as a post-emergence foliar application for many years in wet-seeded rice field in Korea. Since 2009, control of Echinochloa oryzoides with cyhalofop-butyl and penoxsulam was no longer satisfactory. Greenhouse and experiment in rice field were conducted to confirm E. oryzoides resistance to ACCase and ALS inhibitors and to compare herbicide treatments for control of the resistant E. oryzoides to ACCase and ALS inhibitors. Three resistant E. oryzoides to ACCase and ALS inhibitors accessions were tested for levels of resistance to cyhalofop-butyl and penoxsulam, base on survival rate. Iksan and Kimje accessions were not any affected to the survival by treatment with recommended doses of two herbicides tested. Buan accession displayed an intermediate response of 62 and 72% survival at recommended doses of cyhalofop-butyl and penoxsulam, respectively. Survival rates to herbicides mixed with ACCase and ALS inhibitors at 3.5 leaf stage of E. oryzoides was over 80%. Benzobicyclon+fentrazamide+bensulfuron SC, benzobicyclon+mefenacet+bensulfuron SC, benzobicyclone +cafenstrole+pyrazosulfuron-ethyl GR controlled effectively by 2 leaf stage of resistant E. oryzoides to ACCase and ALS inhibitors. In the field experiment, single treatment of benzobicyclon+ fentrazamide+bensulfuron SC and benzobicyclon+mefenacet+bensulfuron SC failed to control E. oryzoides, but squential treatment of benzobicyclon+thiobencarb SE and benzobicyclon+ mefenacet+ bensulfuron SC controlled effectively it in rice infant seedling culture with machine. Our results suggest that resistant E. oryzoides to ACCase and ALS inhibitors had not developed multiple resistance to herbicides with different modes of action. In particular, cafenstrole, fentrazamide, mefenacet were effective control measures.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.179-185
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• 1998

This study was conducted to investigate changes in weed occurrence and dominance as affected by seeding dates in water seeded rice paddy under field following two years of no-tillage condition. The pre-emergence weeds in no-tillage paddy were controlled by glyphosate application at 7 days before seeding. The rice seeds were seeded on April 20, May 10 and May 30, respectively with 40kg/ha of seeding rate. The weed species in the paddy occurred included three species (Echinochloa cursgalli, Aneilma keisak, Ottelia alismoides) of annual weed, one species (Alopecurus aequalis) of biennial weed and five species (Eleocharis kuroguwai, Leersia japonica, Sagittaria pygmaea, Sagittaria trifolia, Potamogeton distinctus) of perennial weed respectively. Aneilma keisak was found to be dorminant on April 20 and May 10 but Eleocharis kuroguwai on May 30 based on number of weeds. The number and dry weight of weeds occurred were higher on May 10 as compared to in other seeding dates, while proportion of perennial weeds increased as the seeding date was delayed. In particular, weed dorminance varied marketly with seeding date. The Simpson's indices were 0.736 on April 20, 0.261 on May 10 and 0.281 on May 30, respectively.

• Korean Journal of Weed Science
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• v.15 no.4
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• pp.289-297
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• 1995

Field experiments were conducted to evaluate the competitive characteristics of weeds with direct-seeded rice. In both dry- and water-seeded rice a weeds) started to grow over the plant height of rice from 45 days after seeding, and there was a great difference in plant height between rice and weeds from 75 days after seeding. Dry weights of weeds drastically increased from 30 days after seeding in both dry- and water-seeded rice, and the increase of dry weight was faster in dry-seeded rice than in water-seeded rice with time. Although weeds competed with rice at earlier growth stages, they did not reduce rice yields and its components until competition period of 75 days after seeding. Required period of weed free at the beginning of the season was 30 to 45 days from seeding in order to avoid any yield loss. The numbers of panicle per plant, spikelets per panicle, grain weight and yield of rice in dry-seeded rice had highly negative correlations with the growth ratios of Echinochloa crus-galli, Ludwigia prostrata, Cyperus difformis, Bidens frondosa, and Cyperus serotinus. In water-seeded rice, the number of plants, panicle per plant, spikelets per panicle and yield had highly negative correlations with growth rate of Echinochloa crus-galli, but the percentage of filled spikelet had negative correlation with Cyperus difformis. Research indicated that in direct-seeded rice weed competition with rice started from 30 days after seeding and significant yield loss by weed competition occurred from 75 days after seeding.

• Korean Journal of Weed Science
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• v.15 no.1
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• pp.30-38
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• 1995

Soil-applied pre-emergence herbicide, pyrazolate(4-(2, 4-dichlorobenzoyl)-1, 3-dimethyl pyrazol-5-yl-p-toluene sulphonate) induced, twist effect of shoots of barnyardgrass under dry conditions, and etiolated leaf and stem of that under water condition. Plant height and root length of rice broadcast on soil surface were similar to the untreated control, but plant height of rice drilled in soil was more inhibited than root length as compared with the untreated control, while development of barnyardgrass seedling was severely inhibited at 20 days after application. The inhibition rate was much higher under water condition than under dry condition, but difference in rice and barnyardgrass did not abserve. However, growth of transplanted rice shown to increase to the untreated control. Shoot and root fresh weight of rice broadcast on soil surface was increase as compared with the untreated control, and that of rice drilled in soil was not affected whereas that of barnyardgrass was severely inhibited by 42% and 41%, respectively. Under dry condition at 20 days after pyrazolate application while root growth of rice broadcast on soil surface under water condition was deadly inhibited and development of barnyardgrass was almost completely inhibited. On the other hand, microscopic studies showed that constriction of mesophyll cell by destruction of chloroplast of barnyardgrass were occurred only under dry condition, whereas damage of rice and barnyardgrass under water and transplanting condition were not observed. Anatomical change in the meristernatic region of rice and barnyardgrass was not occurred, and similar to intact plant regardless of cropping patterns.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.269-277
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• 2002

Ecological studies on entomopathogenic nematodes are required to increase control efficacy against target insect pests and to obtain basic information for mass production. Thus, effect of temperature and nematode concentration on infectivity and reproduction of Steinernema carpocapsae Pocheon and that of exposure time and soil depth on infectivity were examined using Galleria mellonella larvae. Infectivity and reproduction were examined at five temperatures, 13, 18, 24, 30 and 35$^{\circ}C$ with seven concentrations, 0, 5, 10, 20, 40, 80 and 160 infective juveniles (IJs)/larva. Temperature and nematode concentration influenced infectivity and reproduction of S. carpocapsae Pocheon. Although G. mellonella larvae were killed by S. carpocapsae Pocheon at all given temperatures and nematode concentrations, mortality was higher at 24$^{\circ}C$ than other temperatures. Lethal time of G. mellonella by S. carpocapsae Pocheon was shorter with increasing temperature and nematode concentrations. S. carpocapsae Pocheon was not established in G. mellonella at 13 and $35^{\circ}C$. Time for the first emergence from G. mellonella cadaver was longer $18^{\circ}C$ (about 20 days) than 24 and $30^{\circ}C$ (about 5 days). The highest number of progenies was obtained at $24^{\circ}C$ with 80IJs/1arva, i.e., $18.8$\times$10^4$IJs were produced from a larva. In the exposure time assay, G. mellonella death was recorded in 10 minutes when 300 IJs were inoculated per larva. When S. carpocapsae Pocheon was inoculated at the rate of $10^{9}$ IJs/ha to G. mellonella at the depth of 0, 2, 5 and 10 cm of sand columns, 100% mortality and similar sex ratio were observed but number of established IJs in cadaver was decreased with deepening the soil depth. The results indicated that optimum temperature for infectivity and reproduction of S. carpocapsae Pocheon was $24^{\circ}C$ In addition, S. carpocapsae Pocheon was effective to target insects within 5 cm from the soil surface.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.199-211
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• 1994

Butachlor applied pre-emergence at 3.6kg ai/ha inhibited the growth and developments of shoot of barnyardgrass under dry condition, whereas rice was unaffected. Growth of rice and barnyardgrass under water condition was severely inhibited by treatment of butachlor but that of transplanted rice was not affected. The inhibition rate was higher under water condition, in broadcast rice and direct seeded rice than under dry condition, drilled rice and transplanted rice, respectively. The major anatomical response of stem of barnyardgrass seedling to butachlor under dry condition were partial reduction in thickness and collapse of leaf sheath, while not in rice. Broadcast rice on soil under water condition appeared reduction and constriction of leaf primordia thickness, and barnyardgrass formed tubular-like leaves and showed inhibited elongation of apical meristem. On the other hand, transplanted rice did not show these responses.