• Journal of Microbiology and Biotechnology
• /
• v.24 no.9
• /
• pp.1226-1231
• /
• 2014

The rare actinomycete Pseudonocardia autotrophica was previously shown to produce a solubility-improved toxicity-reduced novel polyene compound named $\underline{N}ystatin$-like $\underline{P}seudonocardia$ $\underline{P}olyene$ (NPP). The low productivity of NPP in P. autotrophica implies that its biosynthetic pathway is tightly regulated. In this study, $wblA_{pau}$ was isolated and identified as a novel negative regulatory gene for NPP production in P. autotrophica, which showed approximately 49% amino acid identity with a global antibiotic down-regulatory gene, wblA, identified from various Streptomycetes species. Although no significant difference in NPP production was observed between P. autotrophica harboring empty vector and the S. coelicolor wblA under its native promoter, approximately 12% less NPP was produced in P. autotrophica expressing the wblA gene under the strong constitutive $ermE^*$ promoter. Furthermore, disruption of the $wblA_{pau}$ gene from P. autotrophica resulted in an approximately 80% increase in NPP productivity. These results strongly suggest that identification and inactivation of the global antibiotic down-regulatory gene wblA ortholog are a critical strategy for improving secondary metabolite overproduction in not only Streptomyces but also non-Streptomyces rare actinomycete species.

• Educational Technology International
• /
• v.8 no.2
• /
• pp.21-52
• /
• 2007

Research related to Web-based learning (WBL) has grown exponentially in the last decade. Scholars have explored a variety of areas related to WBL, including techniques, strategies and best practices. One area of particular interest to scholars is the potential of WBL to support and facilitative collaborative learning. Despite the continued exploration, there continues to be a concern related to the theoretical foundations of WBL. The purpose of this article is to explore how different theories may be used to guide research and inform practice in online collaborative learning. We integrate the major points drawn from current research and theory from a variety of perspectives so as to gain a better understanding of how learning is enabled by asynchronous modes of online collaborative learning. We then use this understanding to identify opportunities and challenges for theory development and research in WBL.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.6
• /
• pp.736-741
• /
• 2012

In this study, we analyzed the oxidative stress response of wblA ($\underline{w}$hi$\underline{B}$-$\underline{l}$ike gene $\underline{A}$, SCO3579), which was previously shown to be a global antibiotic down-regulator in Streptomyces coelicolor. Ever since a WblA ortholog named WhcA in Corynebacterium glutamicum was found to play a negative role in the oxidative stress response, S. coelicolor wblA has been proposed to have a similar effect. A wblA-deletion mutant exhibited a less sensitive response to oxidative stress induced by diamide present in solid plate culture. Using real-time RT-PCR analysis, we also compared the transcription levels of oxidative stress-related genes, including sodF, sodF2, sodN, trxB, and trxB2, between S. coelicolor wild type and a wblA-deletion mutant in the presence or absence of oxidative stress. Target genes were expressed higher in the wblA-deletion mutant compared with wild type, both in the absence and presence of oxidative stress. Moreover, expression of these target genes in S. coelicolor wild type was stimulated only in the presence of oxidative stress, suggesting that WblA plays a negative role in the oxidative stress response of S. coelicolor, similar to that of C. glutamicum WhcA, through the transcriptional regulation of oxidative stress-related genes.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.10
• /
• pp.1365-1371
• /
• 2013

The Streptomyces coelicolor wblA gene is known to play a negative role in both antibiotic biosynthesis and the expression of genes responding to oxidative stress. Recently, WhcA, a WblA ortholog protein, was confirmed to interact with dioxygenase-encoding SpiA ($\underline{s}$tress $\underline{p}$rotein $\underline{i}$nteracting with Whc$\underline{A}$) in Corynebacterium glutamicum. We describe here the identification of a SpiA ortholog SCO2553 protein ($SpiA_{sc}$) that interacts with WblA in S. coelicolor. Using heterologous expression in E. coli and in vitro pull-down assays, we show that WblA specifically binds $SpiA_{sc}$, and is influenced by oxidants such as diamide. These data indicate that the interaction between WblA and $SpiA_{sc}$ is not only specific but also modulated by the redox status of the cell. Moreover, a $spiA_{sc}$-disruption mutant exhibited a less sensitive response to the oxidative stress induced by diamide present in solid plate culture. Real-time RT-PCR analysis also showed that transcription levels of oxidative stress response genes (sodF, sodF2, and trxB) were higher in the $spiA_{sc}$-deletion mutant than in wild-type S. coelicolor. These results show that $SpiA_{sc}$ negatively regulates WblA during oxidative stress responses in S. coelicolor.

• Korean Parent-Child Health Journal
• /
• v.4 no.2
• /
• pp.32-42
• /
• 2002

This study was conducted to test the reliability and validity of "What my baby is like(WBL)" that was developed by Pridham et al. for measuring infant temperament. 37 subjects were participated four times-1, 3, 6, and 12months, and 146 cases were analyzed. The construct validity for the scale was tested by factor analysis with four factor loading solution based on the previous study. One item was excluded because total-item correlation was too low, so that the number of total items were eighteen. The analysis yielded four well defined factors: amenability and persistence, activity, reactivity, and adaptability. These four factors explained 57.62% of the variance in the infant temperament. The criterion related Validity was confirmed by the relationship between the infant temperament and HOME, and between the infant temperament maternal confidence in childrearing. The reliability of the scale was determined with Cronbach's alpha coefficient and Guttman split-half coefficient. Cronbach's alpha was .86, for 18 items, and Guttman split-half cofficient was .81. In subscale analysis, Cronbach's alpha was .56~.84. In conclusion, WBL showed a high degree of validity and reliability, suitable in Korean infants for measuring temperament. In the further study, it would be necessary to refine the concept of temperament and to analyze the correlation between WBL and other temperament inventory.

• Knee surgery & related research
• /
• v.30 no.4
• /
• pp.311-318
• /
• 2018

Purpose: The purpose of this study was to evaluate changes in the coronal alignment of the knee and ankle joints after open wedge high tibial osteotomy (OWHTO) to determine factors related to the recurrence (R) of the varus deformity by serial analysis. Materials and Methods: Sixty-four OWHTOs were enrolled in this study. The weight bearing line (WBL) ratio, joint line convergence angle (JLCA), knee joint inclination, mechanical axis-tibial plateau angle, talar inclination (TI), and distal tibia articular angle (DTAA) were serially assessed. Serial correlation analysis between all parameters was performed. Patients were divided into R group and no recurrence (NR) group according to the WBL ratio (55%) at postoperative one year. Results: The preoperative WBL ratio showed significantly negative correlation with serial changes of JLCA, TI, and DTAA (p<0.05). The JLCA, TI, and DTAA as well as WBL ratio showed a significantly larger degree of varus alignment in the R group than in NR group at postoperative 6 weeks and 1 year after OWHTO (p<0.05). Conclusions: Sufficient correction of the WBL and restoration of the JLCA during OWHTO are essential to prevention of the R of varus deformity after the surgery because they are the only modifiable factors during surgery. Level of Evidence: IV, Case series.

• Journal of Ocean Engineering and Technology
• /
• v.16 no.2
• /
• pp.10-20
• /
• 2002

본 논문에서는 바다의 자유표면에서 생성되는 항력에 대한 물리적 특성에 대한 연구가 기술되었다. 2차원 파장(Wave Field) 매개변수해석기법(Parametric Analyzing Technique)을 근거로 한 파경계층(Wave Boundary Layer : WBL)의 1차원 모델로서 항력계산과 파경계층의 특성을 추정하였으며 이론의 간략화(Simplifying)에 대한 연구에 주력하였다.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
• /
• v.5 no.1
• /
• pp.29-39
• /
• 2002

A general investifation into the physical mechanism that is respinsible for drag above the sea surface has been undertaken. On the basis of a ID model of the Wave Boundary Layer(WBL), under a 2D wave field, a parameterization technique for estimation of the drag and mean characteristics of WBL is described. Special attention is paid to estimation of the simplifying assumption of the theory.

• Women's Health Nursing
• /
• v.15 no.3
• /
• pp.224-230
• /
• 2009

Purpose: This study was conducted to investigate infant temperament and mother-infant attachment of breast-feeding mothers with a $5{\sim}7$ month old infant. Methods: This study was descriptive research. The subjects were 258 infants and their mothers participating in 'Year 2007 Healthy Breastfed Baby Contest' on September 5, 2007 and visiting a community health service center from September 1 to December 30 in 2007, The data was gathered by structured questionnaires about the 'maternal attachment inventory (MAI)' and 'what my baby is like (WBL)'. Results: The mean score of WBL was 6.75 and that of MAI was 3.88. In addition, there was a significant positive correlation between the score of infant temperament and mother-infant attachment (r = .33, p < .01). Conclusion: Breast-feeding mothers perceived infant's temperament as more positive, therefore, breast-feeding should be encouraged.

• Microbiology and Biotechnology Letters
• /
• v.40 no.1
• /
• pp.10-16
• /
• 2012

The Streptomyces peucetius OIM (Overproducing Industrial Mutant) strain is a recursively-mutated and optimally-screened strain used for the industrial production of polyketide antibiotics, such as doxorubicin (DXR). Using the S. peucetius OIM mutant strain as a surrogate host, a model minimal polyketide pathway for aloesaponarin II, an actinorhodin shunt product, was cloned in a high-copy conjugative plasmid, followed by functional pathway expression and quantitative metabolite analysis. The level of aloesaponarin II production was noted as being significantly higher in the OIM strain than in the wild-type S. peucetius, as well as in the regulatory network-stimulated S. coelicolor mutant strain. Moreover, the aloesaponarin II production level was seen to be even higher in a down-regulator $wblA_{spe}$-deleted S. peucetius OIM strain, implying that the rationally-engineered S. peucetius OIM mutant strain could be used as an efficient surrogate host for the high expression of foreign polyketide pathways.