• Journal of Plant Biology
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• v.35 no.1
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• pp.61-67
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• 1992

Principal component analysis of the morphological characters was applied to ordinate and examine morphological variation of Enteromorpha linza due to differences in environmental factors. As results, the samples from exposed populations to wave action were characterized by having longer stipe and maximum length, and narrower maximum width than samples from sheltered populations. The results of multiple comparision in each character among populations provided further support for the hypothesized existence of exposed, moderate, and sheltered morphotypes.otypes.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.9
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• pp.129-134
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• 2016

This paper studies the high frequency PWM (pulse width modulation) driving technique to increase an optical efficiency and to prevent an optical color quenching of blue laser for head up display on vehicles using digital micro mirror device (DMD) panel and yellow phosphor wheel. The proposed approach adaptively drives the current pulse width modulated signals of high optical power of blue laser to increase the lifetime and to decrease the stem temperature of laser. This method stabilizes the temperature of laser according to the driving environment and the forward current capacity. By the proposed method, the brightness of blue laser is improved by about 37% compared to the continuous waveform current driving method.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.202-210
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• 2005

Following ingestion, Salmonella must adhere to and colonize the intestinal epithelium of the host in order to establish infection. S. typhimurium synthesize several appendages that are believed to mediate attachment. These include type 1 fimbriae, plasmid-encoded (PE) fimbriae, long polar (LP) fimbriae, and thin aggregative fimbriae. However, the precise roles of these putative adhesins remain unclear, due to conflicting data in the literature. We constructed strains lacking four different fimbriae including type 1 fimbriae, PE fimbriae, LP fimbriae, and thin aggregative fimbriae, as well as strains lacking each fimbriae alone. In cell culture adhesion assays, these mutants adhered to several mammalian cell lines as well as wild-type S. typhimurium. These strains were also screened for virulence in mice, and all strains were virulent or nearly as virulent as their wild-type parents. In contrast, When a strain lacking four fimbriae was screened for virulence in chicks, it was found to be highly attenuated. This suggests a role for either type 1 fimbriae, PE fimbriae, LP fimbriae or thin aggregative fimbriae or a combination of thease fimbriae in the colonization of chicks. It also suggests that differences exist with respect to the surface structures that mediate attachment of Salmonella in chicks as compared with mice.

• Journal of Korean Society of Forest Science
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• v.36 no.1
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• pp.1-4
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• 1977

The variation of isoperoxidase band patterns in the zymograms in the leaves of ${\times}$P. albaglandulosa clones showing excellent growth were observed by starch gel electrophoresis in this study. The results are summerized as follows; The numbers of total bands in the clones were six to eleven. Four to seven were active and one to four were of trace in these bands, and also active bands appeared plentifully in all clones. The appearing pattern of the bands was more monotonous to the cathode than to the anode. Besides, the uniqueness of the isoenzyme forms in each clone made possible to identify the clones, and g and 1 bands were fixed in ${\times}$P. albaglandulosa, ${\times}$P. albaglandulosa being $F_1$ hybrid, the genetic variation of isoenzyme forms was significant statistically.

• Journal of Life Science
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• v.14 no.3
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• pp.400-405
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• 2004

Morphological characteristics of Kalopanox pictus Nakai were studied to examine population differentiation of this species. Based on a phenogram of using 23 morphological characteristics, differentiation of regions were distinct. Collections of 138 specimens from nine populations served as operational taxonomic unit (OTU's) were examined for phenotypic similarity and morphological variation using clustering (Ward's minimum variance method) and principal component analysis (PCA). The first three principal components were responsible for 77.0% of the total variance. Principal component 1 explained 52% of the total variance and was contributed to by the number of palmately parted, the number of pinnately lobed, and width between two lateral lobe apex.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.39-44
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• 2007

The Rqh1 gene is essential for vegetative growth in fission Yeast. The rqh1 mutant showed that sensitivity of DNA damaging agent, a wild range of phenotype including abnormal gene expression and cell elongation. This result showed that the rqhl-overexpression cell was sensitivity to DNA damaging agent like rqhl mutant. When Rqh1 have an over-expression by $nmt1^+$ promoter of pREP vector, rqh1 mutant DNA damaging agent sensitivity could be compensated. We isolated two strong mutant containing complementation gene, rqh156 and rqh172, respectively. This result observed that the DNA damaging agent sensitivity of rqhl mutant was complemented by the expression of rqh156 and rqh172. They induced mRNA expression in a dose-dependent manner HU, MMS and UV. The HU sensitivity of the rqhl was complemented by the expression of rqh156 and rqh172. The mRNA expression of rqh156 decreased on HU dose dependent but the mRNA expression of rqh172 did not decrease on HU dose dependent. The MMS and W sensitivity of the rqhl was complemented by the expression of rqh156 and rqh172. These results indicate that the isolated rqhl gene may play an important role in DNA metabolism.

• Applied Chemistry for Engineering
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• v.23 no.5
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• pp.496-500
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• 2012

Arthrospira platensis (A. platensis) is an economically important filamentous microalgae. The isolation of mutants by chemical or physical mutagen is a clue for the strain improvement. In this study, effects of ultraviolet-B (UV-B) radiation on A. platensis were investigated. Cells (or microalgae) were exposed to UV-B (15 Watt, 254 nm) for 1, 3, 5, and 10 min, and resulting mutants were designated UM1, UM3, UM5, and UM10, respectively. Especially, the lipid content of UM5 mutant was considerably increased by 8~11 fold compared to that of wild types. Moreover, the carotenoid content and antioxidant enzyme (peroxidase and superoxide dismutase) activity were increased. It was shown that UV-induced mutants can accumulate bioactive compounds, which will be useful for the industrial production of valuable products.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.38-45
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• 1993

Gel consistency data collected from various experiments in same location during 1988 to 1992 were analysed to clarify the degree of varietal and environmental variation in rice. Most of japonica and Tongil-type rice varieties were belonged to soft gel consistency, and average gel length of japonica rice was longer than that of Tongil-type varieties. Gel length of glutinous rice cultivars was extremely long, near 100mm. Year variation of gel consistency was recognized, but did not affect on varietal difference. Gel consistency of most rice varieties and pedigree lines tested varied slightly between different seeding dates or nitrogen levels, but gel length of two indica rice varieties were decreased with the later seeding dates or the higher nitrogen levels. Rice varieties belonged to extremely hard or extremely soft gel consistency showed less variation of gel length between different years, seeding dates or nitrogen levels compared with intermediate ones.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.325-330
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• 2007

RNase E is an essential Escherichia coli endoribonuclease that plays a major role in the decay and processing of a large fraction of RNAs in the cell and expression of N-terminal domain consisted of 1-498 amino acids (N-Rne) is sufficient to support normal cellular growth. By utilizing these properties of RNase E, we developed a genetic system to screen for amino acid substitutions in the catalytic domain of the protein (N-Rne) that lead to various phenotypes. Using this system, we identified three kinds of mutants. A mutant N-Rne containing amino acid substitution in the S1 domain (I6T) of the protein was not able to support survival of E. coli cells, and another mutant N-Rne with amino acid substitution at the position 488 (R488C) in the small domain enabled N-Rne to have an elevated ribonucleolytic activity, while amino acid substitution in the DNase I domain (N305D) only enabled N-Rne to support survival of E. roli cells when the mutant N-Rne was over-expressed. Analysis of copy number of ColEl-type plasmid revealed that effects of amino acid substitution on the ability of N-Rne to support cellular growth stemmed from their differential effects on the ribonucleolytic activity of N-Rne in the cell. These results imply that the genetic system developed in this study can be used to isolate mutant RNase E with various phenotypes, which would help to unveil a functional role of each subdomain of the protein in the regulation of RNA stability in E. coli.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.877-880
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• 2005

Purpose : Glycogen storage disease type Ia(GSD Ia) is an autosomal recessive disorder caused by the deficiency of glucose-6-phosphatase(G6Pase). The aim of the study was to investigate the spectrum of G6Pase gene mutations and relationship between genotype and clinical findings in Korean patients with GSD Ia. Methods : Genomic DNA was extracted from peripheral leukocytes of 20 patients with GSD Ia. The five exons of G6Pase gene were amplified and PCR products were directly sequenced. The frequency of short stature, hypoglycemia, hypercholesterolemia, hyperuricemia, hypercalciuria, nephrocalcinosis and hepatic adenoma was compared between 727G>T homozygotes and 727G>T compound heterozygotes. Results : A total of 5 different mutations were identified. The most common mutation was the 727G>T with an allele frequency of 80%. All patients were either homozygous(12/20) or heterozygous(8/20) for the 727G>T mutation. G122D was found in 3 patients, P178A in 1, G222R in 2, and S339R in 2. There was no difference in the frequency of short stature, hypoglycemia, hypercholesterolemia, hyperuricemia, nephrocalcinosis, and hepatic adenoma between 727G>T homozygotes and heterozygotes. Conclusion : Diagnosis of GSD Ia can be based on clinical and biochemical abnormalities combined with mutation analysis instead of enzymatic diagnosis that requires liver biopsy. Homozygosity for the 727G>T does not seem to alter the disease phenotype as compared with the heterozygous state.