• Molecules and Cells
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• v.39 no.8
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• pp.587-593
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• 2016

As sessile organisms, plants must be able to adapt to the environment. Plants respond to the environment by adjusting their growth and development, which is mediated by sophisticated signaling networks that integrate multiple environmental and endogenous signals. Recently, increasing evidence has shown that a bHLH transcription factor PIF4 plays a major role in the multiple signal integration for plant growth regulation. PIF4 is a positive regulator in cell elongation and its activity is regulated by various environmental signals, including light and temperature, and hormonal signals, including auxin, gibberellic acid and brassinosteroid, both transcriptionally and post-translationally. Moreover, recent studies have shown that the circadian clock and metabolic status regulate endogenous PIF4 level. The PIF4 transcription factor cooperatively regulates the target genes involved in cell elongation with hormone-regulated transcription factors. Therefore, PIF4 is a key integrator of multiple signaling pathways, which optimizes growth in the environment. This review will discuss our current understanding of the PIF4-mediated signaling networks that control plant growth.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.1
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• pp.104-112
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• 2003

This paper introduces a thruster attitude control system for the KSR-III and addresses system configuration, design condition for several components and development systems. These systems were confirmed through environmental tests, compatibility tests with other sub-systems and are planned to launch by this year. After the launch test, it can be redesigned for optimal systems using post-analysis.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.146-153
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• 2013

CNG buses has contributed to improve air quality in cities. But it is difficult to meet the next emission regulations such as EURO-VI without the help of additional post-processing device. Hydorgen has higher flame speed and lower combustion temperature that make it thermal efficiency increase with leaner operation. Using hydrogen natural gas blend (HCNG) fuel is promising technology which can reduce $NO_x$ and $CO_2$ emissions for a natural gas vehicle. However, fuel flow rate of HCNG should be increased since hydrogen's energy density per volume is much smaller than natural gas. In the present study, the characteristics of fuel supply system and its applicability were evaluated in a heavy duty natural gas engine. The results showed that the potential of fuel pressure regulator and fuel metering valve had enough capacity with HCNG. Employed mixer did not affect the distribution characteristics of mixture.

• Molecules and Cells
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• v.27 no.4
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• pp.409-416
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• 2009

ADAP is an AP2-domain protein that interacts with ARIA, which, in turn, interacts with ABF2, a bZIP class transcription factor. ABF2 regulates various aspects of the abscisic acid (ABA) response by controlling the expression of a subset of ABA-responsive genes. Our expression analyses indicate that ADAP is expressed in roots, emerging young leaves, and flowers. We found that adap knockout mutant lines germinate more efficiently than wild-type plants and that the mutant seedlings grow faster. This suggests that ADAP is involved in the regulation of germination and seedling growth. Both germination and post-germination growth of the knockout mutants were partially insensitive to ABA, which indicates that ADAP is required for a full ABA response. The survival rates for mutants from which water was withheld were low compared with those for wild-type plants. The result shows that ADAP is necessary for the response to stress induced by water deprivation. Together, our data indicate that ADAP is a positive regulator of the ABA response and is also involved in regulating seedling growth. The role of ADAP is similar to that of ARIA, which is also a positive regulator of the ABA response. It appears that ADAP acts through the same ABA response pathway as ARIA.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.122-130
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• 2013

The object of this study is to review the current states of the characteristics and strategies to control annual bluegrass to apply information to the circumstance of South Korea. Annual bluegrass is one of the most widespread turfgrass species which has great ability to produce seedhead and shoot growth. It also has ability to tolerate low mowing height and to form uniformity of turfgrass when it is established. Annual bluegrass is well-known as weak turfgrass for high and low temperature. High rate of nitrogen and phosphorus improves growth of annual bluegrass. To control annual bluegrass, deep and infrequent irrigation is more effective than light and frequent irrigation. Clipping removal is more effective than clipping return to control annual bluegrass. Prodiamine, bensulide, and dithiopyr are applied as pre-emergence herbicide, and ethofumesate and bisbyribac-sodium are used as post-emergence herbicide. Paclobutrazol and flurprimidol are used as plant growth regulator. Trinexapac which is one of the most popular plant growth regulators (PGRs) in South Korea is not proper to control annual bluegrass because it accelerates improve growth of annual bluegrass in summer. Although chemical control is mainly used in South Korea, combination of cultural and chemical control may be the strategy to maximize effectiveness to control annual bluegrass.

• Korean Journal of Poultry Science
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• v.48 no.2
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• pp.81-90
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• 2021

Avian influenza viruses (AIVs) must utilize host cellular factors to complete their life cycle, and fragile X mental retardation protein (FMRP) has been reported to be a host factor promoting AIV ribonucleoprotein (vRNP) assembly and exports vRNP from the nucleus to the cytoplasm. The functional role of chicken FMRP translational regulator 1 (cFMR1) as a host factor of AIV is, however, poorly understood. In this study, we targeted the cFMR1 gene in DF1 cells using clustered regularly interspaced short palindromic repeats/Cas9-mediated genome editing to examine the functional role of cFMR1 as a host factor of AIV. We found that cFMR1 stimulated viral gene transcription during early stages of the viruses' life cycle and did not affect viral progeny production and viral polymerase activity in DF1 cells 24 hours post infection. cFMR1 overexpression did not exert significant effects on virus production, compared to the control. Therefore, unlike in mammalian systems (e.g., humans or mice), cFMR1 did not play a pivotal role in AIV but only seemed to stimulate viral proliferation during early stages of the viral life cycle. These results imply that the interplay between host factors and AIV differs between mammals and avian species, and such differences should be considered when developing anti-viral drugs for birds or establishing AIV-resistant bird models.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.72-79
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• 1997

A study is a experiment which is figure out to optimum discharge cutting condition of the surface roughness, electronic discharging speed and electrode wear ration with Ton , Toff and V(voltage) as an input condition according to the current(Ip) in an electric spark machine : 1) Electrode is utilized Cu and Graphite. 2) Work piece is used the material of carbon steel. The condition of experiment is : 1) Current is varied 0.7(A) to 50(A) and the time of electric discharging to work piece in each time is 30(min) to 60(min). 2) After the upper side of work piece was measured in radius(5$\mu$m) of stylus analyzed the surface roughness to ade the table and graph of Rmax by yielding data. 3) Electro wear ratio is : \circled1Cooper was measured ex-machining and post-machining by the electronic balance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume $\times$specific gravity and analyzed to made its table and graph on ground the data. 4) In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V. R and the memory scope was sticked to the electric spark machine. 5) In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid , it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1785-1790
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• 2013

The synthetic machinery of ATF4 (activating transcription factor 4) is activated in response to various stress conditions involved in nutrient restriction, endoplasmic reticulum homeostasis, and oxidation. Stress-induced inhibition of proteasome activity triggers the unfolded protein response and endoplasmic reticulum stress, where ATF4 is crucial for consequent biological events. In the current study, we showed that the $NAD^+$-dependent deacetylase, SIRT1, suppresses ATF4 synthesis during proteasome inhibition. SIRT1 depletion via transfection of specific siRNA into HeLa cells resulted in a significant increase in ATF4 protein, which was observed specifically in the presence of the proteasome inhibitor MG132. Consistent with SIRT1 depletion data, transient transfection of cells with SIRT1-overexpressing plasmid induced a decrease in the ATF4 protein level in the presence of MG132. Interestingly, however, ATF4 mRNA was not affected by SIRT1, even in the presence of MG132, indicating that SIRT1-induced suppression of ATF4 synthesis occurs under post-transcriptional control. Accordingly, we propose that SIRT1 serves as a negative regulator of ATF4 protein synthesis at the post-transcriptional level, which is observed during stress conditions, such as proteasome inhibition.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.132-136
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• 1996

A Study is a experiment which is figure out to aptimum discharge cutting condition of the surfaceroughness, electric discharging speed and electro wear ratio with Ton Toff and V(voltage) as an input condition according to the current(Ip) in an electric spark machine ; 1)Electrode is utilized Cu(coper) and Graphite. 2)Work piece is used the material of carbon steel. The condition of experiment is; 1)Current is varied 0.7(A) to 50(A). 2)Pulse time(Ton) is varied 3($\mu$s) to 240($\mu$s) and also Toff is varied 7($\mu$s) to 20($\mu$s). 3)The time of electric discharging to work piece in each time is 30(min) to 60(min) 4)After the upper side of work piece was measured in radius (5${\mu}{\textrm}{m}$) of syulus analyzed the surface roughness to made the table and graph of Rmax by yielding data. 5)Electro wear ratio is; \circled1Coper was measured cx-machining and post machining but the electronic baiance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume specific gravity and analyzed to made its table and graph on ground the data 6)In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V.R(Automatic Voltage Regulator). 7)The memory scope was sticked to the electric spark machine. 8)In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid, it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging According to above results, the surface roughness by the variation of electrodw and current was analyzed to compare KS(Korea Standards) It was decided the optimum condition of electric discharge cutting through analyzing the effect of electric discharge speed and electro wear ratio.

• Journal of Ginseng Research
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• v.47 no.2
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• pp.265-273
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• 2023

Background: The intestinal microbiota is an important regulator of bone health. In previous studies we have shown that intestinal microbiota dysbiosis, induced by treatment with broad spectrum antibiotics (ABX) followed by natural repopulation, results in gut barrier dysfunction and bone loss. We have also shown that treatment with probiotics or a gut barrier enhancer can inhibit dysbiosis-induced bone loss. The overall goal of this project was to test the effect of Korean Red Ginseng (KRG) extract on bone and gut health using antibiotics (ABX) dysbiosis-induced bone loss model in mice. Methods: Adult male mice (Balb/C, 12-week old) were administered broad spectrum antibiotics (ampicillin and neomycin) for 2 weeks followed by 4 weeks of natural repopulation. During this 4-week period, mice were treated with vehicle (water) or KRG extract. Other controls included mice that did not receive either antibiotics or KRG extract and mice that received only KRG extract. At the end of the experiments, we assessed various parameters to assess bone, microbiota and in vivo intestinal permeability. Results: Consistent with our previous results, post-ABX- dysbiosis led to significant bone loss. Importantly, this was associated with a decrease in gut microbiota alpha diversity and an increase in intestinal permeability. All these effects including bone loss were prevented by KRG extract treatment. Furthermore, our studies identified multiple genera including Lactobacillus and rc4-4 as well as Alistipes finegoldii to be potentially linked to the effect of KRG extract on gut-bone axis. Conclusion: Together, our results demonstrate that KRG extract regulates the gut-bone axis and is effective at preventing dysbiosis-induced bone loss in mice.