• Journal of dental hygiene science
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• v.11 no.5
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• pp.463-469
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• 2011

The purpose of this study was to investigate effect of gap between expected job and performed job on job satisfaction and turnover intention in clinical dental hygienists. A total 292 hygienist in dental hospitals and dental offices in nationwide completed a questionnaire on their daily routine job and job which they expected and measured gap between expected job and performed job, such as chairside assisting, preventive care, consultation, reception. The study showed the gap on chairside assisting job among age, career and showed the gap on consultation among age, education, career and showed the gap on reception among age, career. gap on chairside assisting, salary satisfaction, personal day affected job satisfaction and gap on chairside assisting, children, salary satisfaction affected turnover intention. The study showed that salary satisfaction and gap on chairside assisting associated with turnover intention and job satisfaction. Personal day affected job satisfaction but did not affect turnover intention.

• Analytical Science and Technology
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• v.24 no.3
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• pp.212-218
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• 2011

In this study, temporal stability of 5 reduced sulfur compounds (RSCs) including ($H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS) was investigated up to 30 days. To learn the temporal changes in RSC concentration levels, two types of long-term storage experiment were carried out by employing two different approaches for sample storing in Tedlar bag samplers. The first one named as a forward (F) storage method consists of preparing all samples in the beginning of experiment. All these samples were analyzed sequentially through time. The second approach named as a reversed (R) storage method was carried out by preparing each sample through time and by analyzing all of them in the last day. For these experiments, RSC standards were prepared at 10 ppb in 10 L Tedlar bag. The results of both methods were consistent enough to show a tendency of the concentration reduction through time. Moreover, the lightest RSC, $H_2S$ showed the most significant reduction of 84.8% at the end of experiment. To validate difference between these results, t-test was applied to the data obtained between the two methods at 90% significance level. According to t-test, the results of the two approaches were greatly distinguished from 3 RSCs ($H_2S$, $CH_3SH$, and DMDS). The results also indicated that the temporal reduction of RSC differs greatly between light ($H_2S$ and $CH_3SH$) and heavy RSCs (DMS, DMDS, and $CS_2$). The former generally exhibited much significant reduction through time due probably to their lower stability.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.90-95
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• 1999

For the control of the greenhouse whitefly, Trialeurodes vaporariorum entomopathogenic fungi were isolated from forest soils and infected insects. We selected three strains, which showed high pathogenicity and named as SFB-582(Beauveria sp.), SFP-198(Paecilomyces fumosoroseus) and SFV-1053(Verticillium sp.) respectively. Particularly, at the concentration of $10^{7}$ conidia/ml, P. fumosoroseus SFP-198 had the highest pathogenicity, $91.4{\pm}3.5%$ in laboratory. In glasshouse application, $91.4{\pm}3.5%$ SFP-198 showed high protective values($80{\sim}90%$) regardless of developmental stages, which were similar with that of Verticillium lecanii F-903 already reported. Four kinds of formulations of entomopathogenic fungi were developed, formulation with surfactant Silwet L-77 gave best control of greenhouse whitefly(over 90%). These results suggest that P. fumosoroseus SFP-198 is a promising candidate as a microbial pesticide for the control of T. vaporariorum.

• Research in Plant Disease
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• v.19 no.3
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• pp.201-207
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• 2013

This research was performed to establish basic technology for Chinese cabbage clubroot chemical control by investigating the soil contamination of Plasmodiophora brassicae in major producing regions of fall Chinese cabbage. PCR primers were developed to detect P. brassicae, a causal agent of Chinese cabbage club-root that generally occurs in Cruciferae family. A primer set, PbbtgF761 and PbbtgR961, specifically amplified a 245 bp fragment from P. brassicae only. At places well known for fall Chinese cabbage, 10 out of 33 in Haenam-gun, 5 out of 13 in Yeongam-gun and Yeonggwang-gun, 1 out of 6 in Gochang-gun, 2 out of 12 in Hongseong-gun, and 5 out of 17 in Dangjin-si resulted positive for P. brassicae contamination. The results show that the soil contamination rate of P. brassicae was 30.3% in Haenam-gun, 38.5% in Yeongam-gun and Yeonggwang-gun, 16.7% in Gochang-gun, 16.7% in Hongseong-gun, and 29.4% in Dangjin-si. The six places where Chinese cabbage clubroot was visible by naked eye were 100% confirmed by the PCR test of the P. brassicae contaminated soil. Thus, simple PCR test may be utilized as an index to decide on chemical control of P. brassicae.

• Research in Plant Disease
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• v.17 no.1
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• pp.59-65
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• 2011

One hundred Capsicum accessions were screened for symptomatic response and resistance to Tomato spotted wilt virus-pb1 (TSWV-pb1). Symptom and its severity rating were checked by visual observation at 9, 12, 14, and 45 days after inoculation, respectively. Enzyme-linked immune-sorbent assay was performed all tested individuals on non-inoculated upper leaves after the third rating to indentify viral infection. Leaf curling was predominant in almost susceptible individuals of each accession. Stem necrosis was most frequent in wild species while yellowing in commercial hybrids and Korean land race cultivars. Ring spot, a typical symptom of TSWV, was rarely detected in some of a few accessions. Different levels of resistance to TSWV-pb1 were observed among the tested accessions. High level of resistance was detected in 4 commercial cultivars of Kpc-35, -36, -57, and -62, and 8 wild species of PBI-11, C00105, PBC076, PBC280, PBC426, PBC495, PBC537, and PI201238 through seedling test by mechanical inoculation.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.275-283
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• 1987

In order to find out the effectiveness of nitrogen fixation in rhizobia-legume symbiotic relationship, ecological and physiological characteristics of indigenous rhizobia distributed in Korean soils, that is, dissimilatory nitrate reduction patterns of indigenous soybean rhizobia isolated from four different soils, and differences in one-and two-dimensional polyacrylamide gel electrophoretic pattern of proteins among the each subgroups of Bradyrhizobium japonicum and Rhizobium fredii, were investigated. The results were summarized as follows: 1. The indigenous soybean rhizobia isolated from four different soils could be classified into 4 groups depending on growth rate and dissimilatory nitrate reduction pattern, that is, $S_1$ (slow-grower; Bradyrhizobium japonicum and nitrate denitrifier), $S_2$ (slow-grower; Bradyrhizobium japonicum and nitrate respirer), $F_1$ (fast-grower; Rhizobium fredii and denitrifier), and $F_2$ (fast-grower; Rhizobium fredii and nitrate respirer). 2. The population ratio of fast- to slow-growing R. japonicum was 39% to 61%, and the ratio of denitrifier to nitrate respirer was 31% to 69% and 89% to 11% in fast and slow-grower, respectively. Some differences were observed between fast- and slow-growing R. japonicum but no significant difference was observed between denitrifier and nitrate respirer within same growth type by one and two dimensional SDS-polyacrylamide gel electrophoretic patterns.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.189-195
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• 1999

This study was carried out to clarify several factors affecting embryogenesis from anther culture of nine cultivars in Brassica oleracea L. var. italica and to investigate the characteristics of plants derived from anther culture. Androgenesis from anther culture was elevated on the B5 medium supplemented with 0.1mg/L NAA, 0.1mg/L 2.4-D and 10% sucrose. Embryo production in liquid medium was five-fold higher than solid medium. High temperature treatment at 35$^{\circ}C$ for one day before transfer to culture room maintained at $25^{\circ}C$ had effective to induce embryogenesis of cultured anthers but extended treatment at 35$^{\circ}C$ decreased significantly the percent of embryogenesis. Frequency of embryogenesis from cultured anthers exhibited significant difference from 2.8% in 'Green Valiant' to 21% in 'Haisi' as affected by genotypes. Percent of spontaneously dihaploid among regenerated plants from anther culture was ranged from 62 to 74% as affected by the genotypes. Characteristic in relation to plant height, number of leaves and branches, and size of head from anther-derived plants showed differential variation in 'Rokguray' and 'Haisi'. Among these charaters obtained from two cultivars, five lines were selected for early maturity, long plant height and large head. Selected lines were used as breeding meterials for F$_1$ hybrid.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.453-456
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• 2005

This study was carried out to select DNA markers closely linked to brown planthopper (BPH) resistance gene originated from a rice cultivar 'Cheongcheong­byeo'. For the mapping of resistant gene to BPH, a doubled-haploid (DH) population was developed by anther culture of $F_1$ plants from a cross 'Cheongcheong­byeo/Nagdongbyeo'. In BPH bioassay and marker screen­ing for the DH population, the segregation of resistant and susceptible plants to BPH fitted to a 1:1 ratio. A total of 310 RAPDs of 520 markers showed polymorphism in parental survey using 'Cheongcheongbyeo' and 'Nag­dongbyeo'. In the analysis of relationship between BPH resistance and marker pattern for 40 DH lines, the OPE16 produced a specific dominant fragment, 700 bp, which was closely linked with BPH resistance gene of 'Cheong­cheongbyeo'. Based on the linkage analysis using 7 markers, BPH resistance of 'Cheongcheongbyeo' was mapped on chromosome 12, which was closely linked with $OPE16_{700}$ at a distance of 4.6 cM.

• Food Science and Preservation
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• v.24 no.6
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• pp.778-785
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• 2017

This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and $30^{\circ}C$). Baranyi model was used as a primary order model for growth data. The maximum growth rate (${\mu}max$) and lag-phase duration (LPD) for each temperature (except for $10^{\circ}C$ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.236-243
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• 2009

This study was conducted to develop a japonica-type rice cultivar with brown planthopper (BPH) resistance using DNA markers. A doubled haploid (DH) population consisting of 120 pure-lines was established by anther culture of $F_1$ hybrids between 'Samgang', a Tongil type BPH resistance cultivar, and 'Nagdong', a japonica cultivar. To determine the map position of genes responsible for BPH resistance in rice, a genetic map was constructed based on 120 DH lines. A total of 162 molecular markers were classified into 12 linkage groups, covering 1,884 Kosami centimorgan (cM) with an average of 11.6 cM. Five QTLs (qBPR3, qBPR6, qBPR7, qBPR8, and qBPR12) associated with BPH resistance were identified and mapped on chromosomes 3, 6, 7, 8, and 12, respectively, using the genetic map constructed in this study. To analyze the relationship between BPH resistance and agronomic traits, a total of eight QTLs related to the agronomic traits were detected on 12 rice chromosomes. In an analysis of relationships, three QTLs (qBPR3, qBPR7, and qBPR8) showed a linkage with tested agronomic traits. A QTL (qBPR3) located on chromosome 3 (RM282-3023) was closely linked to culm length (qCL3). The QTL (qBPR8) for BPH resistance on the short arm of chromosome 8 also overlapped the region detected in culm length (qCL8).