• Korean journal of applied entomology
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• v.32 no.2
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• pp.176-183
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• 1993

These sutdies were conducted to investigate the joint toxic action of mixtures of several acaricides including amitraz, bifenthrin, propargite, fenbutatin dxide and bxide dicofol to the field-collected strian of Tetranychus urticae. The synergistic action of acaricidal mixtures was greatly varied with the kind of acaricide combinations and their mixture ratios. The combinations of amitraz with each of the tested acaricides were synergized at the given mixture ratios. The higher synergistic action in the each combination was observed at 2 : 8 ratio of amitraz and bifenthrin, 8 : 2 ratio of amitraz and fenbutatin oxide, 4 : 6 ratio of amitraz and propargite and 6 : 4 ratio of amitraz and dicofol.

• Wind and Structures
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• v.4 no.3
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• pp.247-260
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• 2001

In the last three decades several comprehensive field measurement programs have produced significant insight into the wind effects on low-rise structures. The most notable and well published of these efforts are measurements being collected at the Wind Engineering Field Laboratory (WERFL) at Texas Tech University, measurements on low-rise structures in Silsoe, England and measurements on groups of low-rise structures collected in Aylesbury, England. Complementary to these efforts, an additional full-scale field investigation program has recently collected meteorological, pressure, strain and displacement data on a low-rise structure in Southern Shores, North Carolina. To date over seventy-five hundred data sets have been collected at the Southern Shores site in a variety meteorological conditions up to and including hurricane-force winds. This paper provides details of the system, its development, and preliminary assessment of its performance. A description of the field site, the instrumented structure, and the instrumentation system is provided. In addition, an example of the data collected during three hurricanes is presented. The primary goal of this paper is to provide the reader with the necessary technical details to appropriately interpret data from this experiment, which will be presented in future publications currently under development.

• Korean journal of applied entomology
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• v.11 no.2
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• pp.85-89
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• 1972

Fifty-one isolates of Xanthomonas oryzae collected from all over the Korean paddy field were classified as the eight different strains by using four different bacteriophage types. Strain-F was the most prevalent form and strain-H,C, and A followed the strain-F, respectively. Strain-D, however, had not found even single isolate although the strain·D is the most prevalent form at Japan and southern countries of Asia. There was no corelation between the type of strains and the area front which the strain had been collected. Six different types of strains were isolated from IR 667 varieties whereas the three strains were maximum that could isolated from single variety other than IR 667.

• Parasites, Hosts and Diseases
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• v.59 no.3
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• pp.319-324
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• 2021

Incidence of tsutsugamushi disease (scrub typhus) caused by Orientia tsutsugamushi, is steadily increasing. It is a mite-borne disease transmitted by chigger mites. In this study, the chigger mites were collected from field small mammals in Hwaseong-si (city), Gyeonggi-do (province), Korea, 2019 and 2020. The field small mammals captured were 56 Apodemus agrarius (94.9%) and 3 Crocidura lasiura (5.1%). A total of 7,531 chigger mites were collected from the captured small mammals. Using PCR test, 153 chigger mite pools were examined and 17 pools were reported positive for O. tsutsugamushi. The O. tsutsugamushi were identified to 5 strains; Jecheon strain was most prevalent, followed by Boryong strain. The other strains were OI011, Taguchi, and Shimokoshi. Collectively, these results provide essential regional information on mite-borne tsutsugamushi disease in the Hwaseong-si, and further contribute to bring awareness and rapid diagnosis for the tsutsugamushi disease.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.571-576
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• 2010

In this study, an application method of critical strains concept for tunnels' safety by using the values of measured displacements which are obtained in the field is discussed. The aim is to: (1) study on the engineering meanings of critical strains concept by reviewing the previous researches and application examples with measured displacement values; (2) study on the engineering reasonability of critical strains concept with the view point of a tunnel engineering and a geotechnical engineering; (3) study on the features of ground deformation due to tunneling and reciprocal relation between total displacement and measured displacement; (4) evaluate a tunnel safety by using domestic measurements collected in the field; and (5) re-evaluate the control criteria which were previously used in the field, with the view point of critical strains concept. Consequently, it was confirmed that critical strains in the ground has a reasonability and a possibility of unified or common concept with the view point of a tunnel engineering.

• Korean Journal of Veterinary Service
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• v.16 no.1
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• pp.70-75
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• 1993

To determine the prevalence of bovine rotavirus Infection in Chungbuk area, fecal specimen were collected from calves nth diarrhea and tested using ELISA. The positive rates were 53.8%(1 to 30days old), 19.0%(31 to 60days old), and 3.2%(over 60days old). Electrophoretic migration patterns of genomic RNA from field isolates were similar to that of NCDV strain, prototype of bovine rotavirus. Bovine rotavirus field isolate showed characteristic morphology of rotavirus particle with 80nm in diameter, using EM.

• Korean Journal of Veterinary Research
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• v.61 no.3
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• pp.23.1-23.8
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• 2021

Porcine epidemic diarrhea (PED) is characterized by acute enteritis, watery diarrhea, weight loss, dehydration, and death with high mortality in neonatal piglets. In this study, 3 virus isolates collected in Vietnam between 2016 and 2017 were successfully propagated in Vero cells at high virus titers. Sequence analysis of the full-length spike (S) gene revealed that all 3 isolates belong to genogroup 2a, which is closely related to other prevalent Asian strains. Amino acid sequence comparisons revealed 98.19% to 99.13% homology with the Vietnam isolates circulating during 2013-2015, suggesting that field PED viruses (PEDVs) evolve continuously. Experiments in animals demonstrated that antisera from guinea pigs immunized with the vaccine strain resulted in higher levels (5 log₂) of neutralizing antibody against the homologous strain, and showed a relatively lower level of neutralizing antibody against the field isolates. This finding would be helpful in choosing a PEDV strain for vaccine development.

• Korean Journal of Veterinary Research
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• v.63 no.2
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• pp.18.1-18.8
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• 2023

Porcine epidemic diarrhea (PED) is characterized by acute enteritis, watery diarrhea, weight loss, dehydration, and death, with high mortality in neonatal piglets. In this study, 3 virus isolates collected in Vietnam between 2016 and 2017 were propagated successfully in Vero cells at high virus titers. Sequence analysis of the full-length spike (S) gene showed that all 3 isolates belong to genogroup 2b, which is closely related to other prevalent Asian strains. A comparison of the amino acid sequence revealed a 98.19% to 99.13% homology with the Vietnam isolates circulating during 2013-2015, suggesting that field PED viruses (PEDVs) are evolving continuously. Experiments in animals showed that the antisera from guinea pigs immunized with the vaccine strain resulted in higher levels (5 log₂) of neutralizing antibodies against the homologous strain and a relatively moderate level of neutralizing antibodies against the field isolates. This finding would be helpful in selecting a PEDV strain for vaccine development.

• Korean Journal of Microbiology
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• v.24 no.1
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• pp.62-66
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• 1986

Many photosynthetic bacteria capable of hydrogen production were isolated from samples of mud flats of paddy field collected in Kim Hae and Dae Jeo. A strain 230 was selected for the high capability of hydrogen evolution. As the results of examination in physiological, morghological and cultural characteristics, the strain 230 was identified as Rhodopseudomonas sphaeroides.

• Korean journal of applied entomology
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• v.21 no.2 s.51
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• pp.53-60
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• 1982

Isolates of soybean mosaic virus (SMV) strains classified based on virulence in silt resistant soybean cultivars caused the same reactions in soybean cultivars used as differentials as those obtained by sap inoculations to the same cultivars. Five species of aphids (Myzus persicae SULZ., Aphis craccivora KOCH, Aphis citricola VAN., Rhopalosiphum maidis FIT., End R. padi L.) were able to transmit each of SMV strains. However, R. maidis and R. padi were inefficient vectors for transmission of SMV strain G3. Spread if four SMV strains (G2, G3, G6, and G7) was monitored in the field from sapinoculated plants in a one meter row of Williams soybeans (source plants) to plants in an adjacent row of Williams 80cm away (test plants). Test plants wert downwind from the source plants. A complete block design was used. Spread of strain G6 was significantly greater than that of other three strains. Two hundred six aphids were collected from June 27, 1979 to August 2, 1979 in the same field. A. citricola was the mist prevalent, comprising $68\%$ of the total aphids. Yields of Williams inoculated with each strain were also compared. Yields were the least from plants inoculated with strain G2 following G6, G3, and G7 in that order.