• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.42-47
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• 2016

To examine the natural regeneration in the natural mixed-broadleaved forest, flowering, fruiting, seed-fall, and seed viabilities of Acer pseudosieboldianum (Ap) were investigated in Mt. Jungwang, Gangwon-do, from 2009 to 2015. The flower of Ap consisted many male and bisexual flowers on the corymb. Flowering dates are differed between sex morph in the same inflorescence. Stamens are stop growing and disappeared after pollinated pistil begin to grow in bisexual flowers, and male flowers have vestial pistil. The flowers of Ap might be pollinated by Apis mellifera, Andrenidae spp. and Syrphinae spp. Ap had some mechanism to prevent from self pollination with heterodichogamy. Mean annual seedfall of Ap was 70,780 ea/ha (ranged 310~234,840 ea/ha). Annual seedfall of Ap varied severely, and the maximum was about 760 times the minimum. Annual seed production of Ap might be to a normal distribution. Rates of damaged or decayed seeds are highest 59.3%, and those of sound seeds are 23.9%, Those of undeveloped and empty seeds are 9.2% and 7.6%, respectively. The most important factors influencing sound seed production might be the density and activities of insect pollinators and sucking pest in the flowerwing period, middle-late May. Successful regeneration of Ap might be in masting year and on the gap sites with proper conditions to germinate and grow. To understand the natural regeneration of deciduous hardwoods, further study on the characteristics of flowering and fruiting, pre- and post-dispersal seed predation, and annual variation on these factor should be needed.

• Journal of Life Science
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• v.24 no.2
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• pp.196-208
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• 2014

During the life cycle of plants, water deficit leads to an adverse effect on its growth and development. To increase the productivity of crops, overcoming such drought stress is one of the most important issues in the field of plant study. Among plant hormones, the phytohormone, abscisic acid (ABA) plays a crucial role in eliciting resistance to drought stress as well as in multiple developmental processes, such as seed germination, stomatal closure, and seedling growth. Therefore, further understanding of the ABA-mediated signal transduction pathway in plants is an effective strategy to generate drought-tolerant plants. Posttranslational modification, such as phosphorylation and ubiquitination, is an efficient mechanism for plants to acquire quick adaptation against environmental stress conditions since this process directly affects pre-existing signaling components by modulating protein activity and stability. Here, recent reports on ABA signaling are reviewed, especially focusing on ABA transport, perception, signaling, and posttranslational modification in ABA-mediated cellular responses. Also, we present future prospects on how the control of such a mechanism can be applied to generate useful agricultural crops.

• Journal of Life Science
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• v.26 no.3
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• pp.353-358
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• 2016

Thiolase is an enzyme that catalyzes condensation reactions between two acetyl-CoA molecules to produce acetoacetyl-CoA. As thiolase catalyzes is the first reaction in the production of n-butanol, knowledge of the molecular and regulatory mechanism of the enzyme is crucial for synthesizing high-value biofuel. Thiolase from Clostridium butyricum (CbTHL) was expressed, purified, and crystallized. X-ray diffraction data were collected from the crystals, and the 3-dimentional structure of the enzyme was determined at 2.0 Å. The overall structure of thiolase was similar to that of type II biosynthetic thiolases, such as thiolase from C. acetobutylicum (CaTHL). The superposition of this structure with that of CaTHL complexed with CoA revealed the residues that comprise the catalytic and substrate binding sites of CbTHL. The catalytic site of CbTHL contains three conserved residues, Cys88, His349, and Cys379, which may function as a covalent nucleophile, general base, and second nucleophile, respectively. For substrate binding, the way in which CbTHL stabilized the ADP moiety of CoA was unlike that of other thiolases, whereas the stabilization of β-mercaptoethyamine and pantothenic acid moieties of CoA was quite similar to that of other enzymes. The most interesting observation in the CbTHL structure was that the enzyme was regulated through redox-switch modulation, using a reversible disulfide bond.

• Journal of Life Science
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• v.26 no.3
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• pp.338-345
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• 2016

This study investigated the antioxidant and anti-inflammatory activity of ethanol extract from the flowers of Weigela subsessilis (WS-E) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The total polyphenol and flavonoid content was 719.19±0.04 μg tannic acid equivalents/ml and 644.87±0.02 μg quercetin equivalents/ml, respectively. The antioxidant activities of WS-E were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radical scavenging activity. The antioxidant activities of WS-E increased markedly, in a dose-dependent manner. To screen for anti-inflammatory agents, the inhibitory effects of WS-E on the production of proinflammatory cytokines in the LPS-stimulated RAW 264.7 macrophages was examined. WS-E had no effect on cell viability at a concentration of 100 μg/ml. Nitric oxide (NO) and interleukin (IL)-6 production were inhibited in a dose-dependent manner (p<0.05). WS-E had no effect on the production of tumor necrosis factor (TNF)-α at a concentration of 0.16–20 μg/ml but induced TNF-α at a concentration of 100 μg/ml. Inducible nitric oxide synthase (iNOS) expression was also inhibited at lower concentrations (p<0.05). In addition, WS-E reduced the activation of nuclear factor (NF)-κB by inhibition of inhibitoy (I) κB phosphorylation in RAW 264.7 macrophages upon stimulation with LPS (100 ng/ml) for 24 h but not that of mitogen-activated protein kinase (MAPK). These results suggest that WS-E may be a useful antioxidant and anti-inflammatory agent in functional cosmetics.

• Korean Security Journal
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• no.50
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• pp.265-283
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• 2017

The purpose of this study is to examine the effects of job stress on Organizational commitment and turnover intent with targets of Employees of Security Industry. A total of 156 answered questionnaires were used as final data. The following conclusions were obtained by conducting correlation analysis and multiple regression analysis using SPSS 18.0 statistical program. First, it is found that Organizational commitment effects some sub-factors of job stress such as inappropriate compensation, insufficient job control and job requirements. Second, it is found that turnover intent affects some sub-factors of job stress such as inappropriate compensation, insufficient job control and job requirements. Third, it is found that turnover intent affects Organizational commitment. Based on the result of the research, job stress seems to affect organizational commitment and people's decisions to change jobs. The two variables job stress and organizational commitment act as key factors in deciding whether to change jobs, while organizational commitment plays as an important parameter. In other words, there should be principles to do work along with channels through which workers communicate with each other. To this end, there need to be programs educating people to work together as well as systematic assistance and support to encourage people to develop their expertise.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.339-344
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• 2005

Rice blast, which is caused by the fungus Magnaporthe grisea, is one of the most destructive diseases of rice. To identify genes involving in the signal transduction pathways that mediate rice blast resistance, we screened over 2,000 mutant lines of a highly resistant variety RIL260 that were generated by using a DEB (1, 3-Butadiene diepoxide) treatment method. In the mutant population, the frequency of albino plants was 6.7%, indicating that this population has a high frequency of mutations in the genome. The primary screening identified 29 mutant plants that exhibit a complete or partial loss of the resistance to rice blast. Among them, M5465, the most susceptible line, was subsequently examined by DNA gel-blot experiments using DNA molecular markers of Pi5(t) that has been previously identified as a durable resistance locus in RIL260. The result revealed that a large deletion and rearrangement of genomic DNA occurred in the Pi5(t) locus. The results suggest that DEB can be used as an efficient mutagen to induce large scale mutations in the rice genome. The isolated mutants should be useful for elucidating the Pi5(t)-mediated signaling pathways of rice blast resistance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.69-78
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• 2017

Shannon of the 5G smartphone and Fourier of the signal processing meet in the sampling theorem (2 times the highest frequency 1). In this paper, the initial Shannon Theorem finds the Shannon capacity at the point-to-point, but the 5G shows on the Relay channel that the technology has evolved into Multi Point MIMO. Fourier transforms are signal processing with fixed parameters. We analyzed the performance by proposing a 2N-1 multivariate Fourier-Jacket transform in the multimedia age. In this study, the authors tackle this signal processing complexity issue by proposing a Jacket-based fast method for reducing the precoding/decoding complexity in terms of time computation. Jacket transforms have shown to find applications in signal processing and coding theory. Jacket transforms are defined to be $n{\times}n$ matrices $A=(a_{jk})$ over a field F with the property $AA^{\dot{+}}=nl_n$, where $A^{\dot{+}}$ is the transpose matrix of the element-wise inverse of A, that is, $A^{\dot{+}}=(a^{-1}_{kj})$, which generalise Hadamard transforms and centre weighted Hadamard transforms. In particular, exploiting the Jacket transform properties, the authors propose a new eigenvalue decomposition (EVD) method with application in precoding and decoding of distributive multi-input multi-output channels in relay-based DF cooperative wireless networks in which the transmission is based on using single-symbol decodable space-time block codes. The authors show that the proposed Jacket-based method of EVD has significant reduction in its computational time as compared to the conventional-based EVD method. Performance in terms of computational time reduction is evaluated quantitatively through mathematical analysis and numerical results.