• Research in Plant Disease
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• v.14 no.2
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• pp.117-121
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• 2008

To determine the economic threshold level of Meloidogyne incognita on cucumber in greenhouse conditions, cucumber seedlings(Cucumis sativa L. cv. 'Super Manchon') grafted on 'Jangsushintozoa'(Cucurbita maxima x Cu. moschata) were planted in wooden boxes($30{\times}40{\times}15cm,\;L{\times}W{\times}D$) under a plastic house in August 01 and harvested from Sep. 01-Oct. 30, 2006. The initial nematode population densities(Pi) in the wooden boxes were adjusted to 0, 10, 30, 100, 300, and 600 second-stage juveniles(J2)/100 $cm^3$ soil. The relationship of total fruit yield to Pi level could be adequately described by a linear regression equation, $Y=0.82-0.04{\cdot}Log_{10}$(Pi+1). Initial nematode densities(Pi) before planting in excess of 5 J2/1,000 $cm^3$ soil caused in total yields loss that is equivalent to the costs of granular nematicide application; Pi level in excess of 25 J2/1,000 $cm^3$ soil caused in total yields loss that exceed the costs for application of fumigants at current control costs. We propose two different management strategies depending on nematode densities, (i) application of non-fumigant granular nematicides for M. incognita Pi level of 5 J2/1,000 $cm^3$ soil and (ii) fumigant treatment with Pi level over 25 J2/1,000 $cm^3$ soil. Soil samples to determine population density of Meloidogyne spp. for advisory purposes should be taken several months before planting time, which allows a period of time enough for implementing management procedures.

• Investigative Magnetic Resonance Imaging
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• v.7 no.1
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• pp.31-38
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• 2003

Purpose : To analyze the serial changes of proton magnetic resonance (MR) spectra in the abscess and to determine the effect of the antibiotic treatment on the metabolite patterns. Materials and Methods : MR imaging and MR spectroscopy of an experimentally induced abscess were performed sequentially for four weeks at interval of one week in both the control group (n=5) and the antibiotic treatment group (n=5). On MR imaging, the shape and the size of the abscess were analyzed. On MR spectroscopy, the resonance peaks of metabolites were assigned on the basis of reported peaks in the literature. The metabolite ratios measured by using N-acetyl alanine as an external reference and by using lipid as an internal reference were compared in both the control and treatment g roups. Results : The abscesses were seen as cystic masses on MR imaging. On MR spectroscopy, the variable peaks of acetate, succinate and various amino acids, which are the metabolites of infection, were identified in the control and antibiotic treatment groups. The most frequent peak was that of acetate at 1.92ppm (70%). Both the peak ratios of acetate to lipid and acetate to external reference tended to decrease in the treatment group while the ratios did not change significantly in the control group. Conclusion : MR spectroscopy is useful not only for the diagnosis of abscess but also for monitoring the evolution of the abscess by using the acetate peak.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.333-337
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• 2006

The damage aspects of soybean by common cutworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) at different larval density and different growth stage of soybean were studied in soybean field. The percent yield reduction(Y) of soybean infested by different densities of S. litura (X, no. of larvae/plant) under outdoor conditions for a three week period were estimated by the following equations: (1) Y = 1.655X - 6.025 ($R^{2}=0.952$) for the R1 (flowering stage); (2) Y = 0.725X - 0.475 ($R^{2}=0.986$) for the R3 (beginning pod stage); and (3) Y = 0.635X - 1.325 ($R^{2}=0.986$) for the R5 (beginning seed stage). Based on the relationships between the densities of S. litura larvae and the yield index of soybean, the number of larvae (2nd-3rd instar) which caused 5% loss of yield (Tolerable injury level) was estimated to as approximately 6.7 for the R1, 7.5 for the R5, and 10.0 per plant for the R5, respectively. Average soybean leaf areas consumed by 1st, 2nd, 3rd, 4th, 5th and 6th larvae of Spodoptera litura during 24 hr at $28^{\circ}C$ was 0.3, 0.7, 2.6, 4.0, 20.1, and $55.8\;cm^{2}$, respectively.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.275-282
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• 2006

Insect pests attacking the leaf of lettuce (Lactuca sativa) were surveyed in environmentally frendly leaf-lettuce-greenhouses in Hwaseong, Namyangju, and Suwon from 2003 to 2004. Sixteen insect species of eleven families in eight orders were collected in greenhouses. Among them, Acyrthosiphon solani, Frankliniella occidentalis, and Autographa nigrisigna were the most serious pest species because of their damage ratio was over 30%. Population of Acyrthosiphon solani showed the highest peak one or two times between mid-April and early June in both the second and the third cropping period. Frankliniella occidentalis reached the highest peak one or two times, the first peak between mid-June and the late July, and the second peak between the mid-August and the mid-October.Autographa nigrisigna reached the highest peak one or times between early June and late July and in the mid-August to late October. The highest peak occurrence of A. solami was observed in early June as many as 4,836 nymphs and adults per 100 leaves. And for F. occidentalis it was in early July occurring 437 larvae and adults per 100 leaves, for A. nigrisigna in early October occurring 42 larvae per 100 leaves. The density of F. occidentalis and its damage as well was greater in soil culture than in hydroponic culture, but in case of both A. solani and A. nigrisigna no such difference between cropping systems was found.

• Korean journal of applied entomology
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• v.54 no.1
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• pp.1-6
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• 2015

This study was conducted to estimate the economic injury level (EIL) to leaf broccoli (leaf vegetable) by the diamondback moth (Plutella xylostella L.) in 2007 and obtain basic data for pest management. To investigate the relationship between initial density of diamondback moth larvae and broccoli leaf yield, experimental plots with five treatments (0, 0.5, 1.0, 1.5 and 2.0 larvae per plant) as initial density were established. We inoculated larvae on cheesecloth covering to survey changes in larval density. When grown for consumption, leaves of broccoli are harvested in periods. High levels of larvae were associated with significant reductions in leaf yield. There were 0%, 15%, 35%, 42%, 44% yield reductions due to a density of 0, 0.5, 1.0, 1.5, 2.0 diamond back moth larvae per plant, respectively, 25 days after larva inoculation. The regression equation used to predict leaf yield based on the number of initial larvae per plant was y = 1636-394x($R^2=0.79^{***}$>). EIL of the diamondback moth on leaf broccoli was 2~3 larvae per 10 plants for a damage level of 5%. The economic threshold was 1~2 larvae per 10 plants. Thus, diamondback moth management should be initiated when 1~2 larvae appear on 10 plants.

• Parasites, Hosts and Diseases
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• v.22 no.2
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• pp.153-160
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• 1984

An experimental study was undertaken to observe the difference in susceptibility of mouse strains to Metagonimus yokogawai infection by estimating it from worm recovery rate and dimension of worms. It was also studied the effects of prednisolone injection on the chronological pattern of worm recovery in ICR mice. The metacercariae were obtained from sweetfish and 300 in each number were given to 5 strains (CBH, A, DBA, $C^{57}BL$ and KK) of mice, and after 7 days period, the worms were collected from their intestine. Prednisolone at the dose of 10 mg/kg was injected to ICR mice every other day from 7 days prior to infection until sacrificed at 6 hours to 35th post-infection day. ICR mice infected with M. yokogawai but untreated were used for controls. The success rate in infection of mice ranged 25.0-83. 3% by strains, the worm recovery rate 1. 2-18. 9%, and the average size of worms O. 554-0. 683 mm long and 0.214-0.244 mm wide. The higher rates and larger size of worms were observed in KK and $C^{57}BL$ strains than others and the difference was statistically significant. In ICR mice for control, the worm recovery rate until 1 day after infection was relatively high (38-66%) but it became much lower (less than 0.7%) during 1-35 days. However, prednisolone injection brought about persistently high recovery rates (16-80%) until 21 days. It was concluded that the susceptibility to M. yokogawai infection is different by strains of mice but it can be elevated by prednisolone injection probably due to suppression of Immune respon3e3 in ICR mice.

• Journal of Veterinary Clinics
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• v.29 no.3
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• pp.237-241
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• 2012

Colonic transit time plays an important role in creating a disease category and treatment plan in patients with chronic constipation or bowel movement problem. The aim of this study is to establish normal colon transit time using Kolomark, a radiopaque marker in dogs. The transit time of Kolomark in colon was measured every 2, 4, 8, 12, 24, 48 hours in 11 healthy Beagle dogs with oral administration of the marker. Kolomark began to appear in colon after 4 hours from administration and the largest number of Kolomark in colon was observed after 12 hours. Then, after 24 hours, some quantity of Kolomark was found but Kolomarks were all eliminated from the colon after 48 hours. The mean emptying time of Kolomark was 28.36 hours. Based on this study, the normal range of colon transit time in dogs was established by using the Kolomark, and it could be used as reference data for objective evaluation of constipation in canine patients.

• Journal of fish pathology
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• v.19 no.1
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• pp.65-72
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• 2006

Nervous necrosis virus (NNV) that causes severe mortality during seed production of red drum (Sciaenops ocellatus) is known to be vertically transmitted from infected spawners. This study was conducted to produce NNV free seeds by testing spawners for NNV infection and using virus free eggs for seed production. RT-PCR analysis of 40 spawners showed 18 positives and 22 negatives. NNV was not detected from eggs obtained from the negative spawners but was detected from those obtained from the positives. NNV was not detected from culturing seawater in tanks and Chlorella spp., Brachionus plicatilis., and Brine shrimp those were provided as live feed. The survival rates of fry from NNV positive and negative spawners were 80% and 85%, respectively by two weeks after hatching. The mortality increased from 25days after hatching and the final survival rate of seeds from NNV positive and negative spawners were 0% and 18.3%, respectively on 41 days after hatching. These results suggested that virus free red drum seeds can be obtained by using virus-free spawners.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.2
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• pp.161-167
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• 2013

In animal experiments for EMF exposure, it is very important to estimate the SAR values accurately in animals. In this paper, we investigated the variation of SAR values in mice and rats, depending on the number and separation distance of animals and the existence of the water-supplying bottle. The whole-body of mice or rats in a cage were exposed in the reverberation chamber at CDMA and WCDMA frequencies. Simulation results show that the variation of the whole-body averaged SAR is larger when several animals are exposed in a cage, compared to the existence of water-supplying bottle and the amount of water. It turns out that compared to single mouse or rat is located in the cage, the maximum variation of the whole-body averaged SAR values for mice at 850 MHz and 1,950 MHz are 15.3 % and 14.9 % when three mice are located in the cage, and those for rats are 18.7 % and 21.1 % for each frequency when two rats are located in the cage. It is concluded that the variation of SAR values depending on the exposure conditions in real situation cannot be ignored.

• Progress in Medical Physics
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• v.21 no.4
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• pp.348-353
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• 2010

The purpose of this study was to explore the potentials of a clinical 3T MRI in mouse brains and technical adaptation and optimization. T1-weighted images (T1WI), T2-weighted images (T2WI), FLAIR (Fluid Attenuated Inversion Recovery) images, Gadolinium enhanced T1-weighted images (Gd-T1WI), Diffusion weighted images (DWI) were acquired in brain of 2 mice (weight 20~25 g) with cerebral infarction by occlusion of right middle cerebral artery, 1 hour, 24 hours, 72 hours after infarction and 1 normal mouse brain using clinical 3T MRI scanner. We analyzed differentiation of striatum, ventricle, cerebral cortex, and possibility of detection of acute cerebral infarction. We could differentiate the striatum, ventricle, cerebral cortex on T2WI and on DWI, FLAIR, T1WI, the differentiation of each anatomy of brain was not definite, but acute cerebral infarction was detected on DWI of 1 hour, 24 hours, 72 hours after infarction and on T2WI, FLAIR of 24 hours, 72 hours after infarction. Clinical 3T MRI can be used in differentiation of anatomy of mouse brains and DWI can be helpul in detection of acute cerebral infarction in acute phase. With technical adaptation and optimization clinical 3T MRI can be useful tool for provide preclinical and clinical small animal studies.