• Cross-Cultural Studies
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• v.33
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• pp.193-239
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• 2013

A photograph, which was applied to contemporary art, plays a very important role in the whole of the multiplied and diversified contemporary arts today. The application of photos, which were shown in contemporary art following the 1950s, can be classified into five types according to role and function of a photo in the process of developing a work. However, this classification is shown a little ambiguously. That is because photos of being utilized by artists are indicated very diversely depending on their artistic strategy and situation. As the first type, a few painters utilize a photo as mirror of reality in order to materialize a challenging and revolutionary idea with going against traditional picture in their pictorial practice. As the second classification, especially American painters utilize a photo as material component of forming their picture like photo-montage or collage. The combined application of this medium is first doing genre de-construction and hybridization of post-modernism in the 1980s while ultimately aiming at social criticism or political satire. The third type implies particularly a case that avant-garde artists utilize a photo as evidence of a work. In this case, a photo is employed as evidence of a work, which disappears in the temporal space essentially like body art, land art, and performance. Also, as the fourth type is a case of utilizing a photo for artistic concept of a work, not pictorial practice of picture, it is utilized often as important artistic strategy of conceptual artists. The final type of utilizing photo is a case of applying photo as formative tool on behalf of dye-stuffs or crayon in order to record a section of reality, which always continues regardless of event or meaning any more, in the traditional picture. In this case, a work is indicated as a photo of having a form of picture, namely, as Forme-tableau. The main subject is indicated there as a daily case of being repeated always the extremely common and revived theme.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1818-1825
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• 2007

S-Adenosylmethionine (SAM) was previously documented to activate secondary metabolism in a variety of Streptomyces spp. and to promote actinorhodin (ACT) and undecylprodigiosin (RED) in Streptomyces coelicolor. The SAM-induced proteins in S. coelicolor include several ABC transporter components (SCO5260 and SCO5477) including BldKB, the component of a well-known regulatory factor for differentiations. In order to assess the role of these ABC transporter complexes in differentiation of Streptomyces, SCO5260 and SCO5476, the first genes from the cognate complex clusters, were individually inactivated by gene replacement. Inactivation of either SCO5260 or SCO5476 led to impaired sporulation on agar medium, with the more drastic defect in the SCO5260 null mutant (${\Delta}SCO5260$). ${\Delta}SCO5260$ displayed growth retardation and reduced yields of ACT and RED in liquid cultures. In addition, SAM supplementation failed in promoting the production of ACT and RED in ${\Delta}SCO5260$. Inactivation of SCO5476 gave no significant change in growth and production of ACT and RED, but impaired the promoting effect of SAM on ACT production without interfering with the effect on RED production. The present study suggests that SAM induces several ABC transporters to modulate secondary metabolism and morphological development in S. coelicolor.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.51.3-52
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• 2018

Since Voyager 1 passed the Heliopause in 2012, it has provided the observations of the charged particles in the local interstellar medium. However, Voyager 1 only provides the information along with its trajectory. In order to understand the global view of the interstellar plasma flow surrounding the Heliopause, we need another tool. When the interstellar plasmas approach the Heliopause, the ions are deflected around the Heliopause due to the draping of the interstellar magnetic field. The draping of the interstellar magnetic field is strongly connected with the shape of the Heliopause. A fraction of the diverted ions exchanges their charges with the undisturbed primary interstellar neutral atoms, and then the ions become neutral atoms called the secondary interstellar neutral atoms. The newly created neutral atoms carry information on the diverted flow of the interstellar ions, and a fraction of them can travel to the Sun. Therefore, the secondary component of the interstellar neutrals is an excellent diagnostic tool to provide important information to constrain the shape of the Heliopause. The secondary interstellar neutrals are observed by Interstellar Boundary Explorer (IBEX) at Earth's orbit. Since 2009, two energetic neutral atom cameras on IBEX have measured neutral atoms and it has provided sky maps of neutral atoms. In this presentation, we will discuss the directional distribution of the secondary interstellar neutrals at Earth's orbit. In the sky maps, the primary interstellar neutral gas is seen between $200^{\circ}$ and $260^{\circ}$ in ecliptic longitude and the secondary components are seen in the longitude range of $160^{\circ}-200^{\circ}$. We also present a simplified model of the outer heliosheath to help interpret the observations of interstellar neutrals by the IBEX-Lo instruments. We extract information on the large-scale shape of the Heliopause by comparing the neutral flux measured at IBEX along four different look directions with simple models of deflected plasma flow around hypothetical obstacles of different aspect ratios to the flow. Our comparisons between the model results and the observations indicate that the Heliopause is very blunt in the vicinity of the Heliospheric nose, especially compared to a Rankine half-body or cometary shape.

• Wind and Structures
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• v.20 no.6
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• pp.763-791
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• 2015

"Wind and Ports" is a European project that has been carried out since 2009 to handle wind forecast in port areas through an integrated system made up of an extensive in-situ wind monitoring network, the numerical simulation of wind fields, the statistical analysis of wind climate, and algorithms for medium-term (1-3 days) and short term (0.5-2 hours) wind forecasting. The in-situ wind monitoring network, currently made up of 22 ultrasonic anemometers, provides a unique opportunity for detecting high resolution thunderstorm records and studying their dominant characteristics relevant to wind engineering with special concern for wind actions on structures. In such a framework, the wind velocity of thunderstorms is firstly decomposed into the sum of a slowly-varying mean part plus a residual fluctuation dealt with as a non-stationary random process. The fluctuation, in turn, is expressed as the product of its slowly-varying standard deviation by a reduced turbulence component dealt with as a rapidly-varying stationary Gaussian random process with zero mean and unit standard deviation. The extraction of the mean part of the wind velocity is carried out through a moving average filter, and the effect of the moving average period on the statistical properties of the decomposed signals is evaluated. Among other aspects, special attention is given to the thunderstorm duration, the turbulence intensity, the power spectral density and the integral length scale. Some noteworthy wind velocity ratios that play a crucial role in the thunderstorm loading and response of structures are also analyzed.

• Journal of the Korean Ceramic Society
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• v.13 no.1
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• pp.35-44
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• 1976

The effect of quartz which exists in clays, especially in kaolin used for the production of chamotte sagger, on the strength of refractory was examined. In this study, a mixture of chamotte 50%, kaolin 25%, plastic clay 25% in ternary component system was selected as a batch composition. To this mixture 1%, 3% and 5% of feldspar and sericite were added respectively. The plastic clay used here was separated under 170 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. In order to change the particle size and the content of quartz, the kaolin was separated under 60, 115, 170 and 325 mesh by wet process, substituted quartz for coarse parts of it. Chamotte was classified into three grades, coarse (5-10mesh): medium (10-20mesh): fine(20-115mesh) and the ratio was 1:1:1. Samples were formed in 0.8xIx10cm size with 12.5% water at 160kg/$\textrm{cm}^2$ pressure, and fired at 130$0^{\circ}C$ for 1 hr. The fired samples were ivnestigated by means of x-ray diffraction analysis and microscopic observation, and the physical properties of them were also examined, such as firing shrinkage, apparent specific gravity and bulk specific gravity, apparent porosity, water absorption and modulus of rupture. The obtained results are as follows: 1. When screened kaolin with low content of quartz was added to fixed chamotte-plastic clay system, the sample lowered modulus of rupture and increased apparent porosity as the size of kaolin became finer. 2. When kaolin under 325 mesh with 7.2-15.81% quartz between 60-325 mesh was added to fixed chamotte-plastic clay system, the sample had higher apparent porosity and lower modulus of ruputure as the size and the amount of quartz became larger. 3. The addition of feldspar and sericite to chamotte-plastic clay system improved apparent porosity and modulus of rupture. The effect of feldspar was better when quartz content was low, although that of sericite was better than quartz content was high.

• Korean Journal of Medicinal Crop Science
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• v.23 no.5
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• pp.357-362
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• 2015

Background : A series of studies were conducted to optimize adventitious root induction in vitro from explants of Astragalus membranaceus using various nutrient media supplemented with plant hormones. Methods and Results : Levels of active components were analyzed from adventitious roots induced under different media conditions. Among the different media conditions, Murashige and Skoog medium supplemented with $1.0mg{\cdot}{\ell}^{-1}$ indole-3-butyric acid resulted in the greatest adventitious root induction rate. The amount of the major active component of the adventitious roots of Ama1, calycosin-7-O-${\beta}$-D-glucopyranoside was higher than that of other adventitious root samples. Conclusions : These results suggest that the adventitious roots of A. membranaceus could be used for the commercial production of medicines.

• Journal of Ginseng Research
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• v.38 no.3
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• pp.215-219
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• 2014

Background: Biological control of plant pathogens using benign or beneficial microorganisms as antagonistic agents is currently considered to be an important component of integrated pest management in agricultural crops. In this study, we evaluated the potential of Bacillus subtilis strain HK-CSM-1 as a biological control agent against Colletotrichum panacicola. Methods: The potential of B. subtilis HK-CSM-1 as a biological control agent for ginseng anthracnose was assessed. C. panacicola was inoculated to ginseng plants and the incidence and severity of disease was assessed to examine the efficacy of the bacterium as a biological control against C. panacicola. Results: Inoculation of Panax ginseng plants with B. subtilis significantly suppressed the number of disease lesions of C. panacicola and was as effective as the chemical fungicide iminoctadine tris(albesilate). The antifungal activity of B. subtilis against C. panacicola was observed on a co-culture medium. Interestingly, treatment with B. subtilis did not significantly affect the diameter of the lesions, suggesting that the mechanism of protection was through the reduction in the incidence of infection related to the initial events of the infection cycle, including penetration and infection via spore germination and appressorium formation rather than by the inhibition of invasive growth after infection. Conclusion: Our results suggest that B. subtilis HK-CSM-1 can be used as an effective and ecologically friendly biological control agent for anthracnose in P. ginseng.

• Korean Journal of Medicinal Crop Science
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• v.19 no.6
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• pp.441-445
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• 2011

This research was conducted to investigate the influence of variouis organic substrates on growth and yield of organically grown ginseng seedlings in a shaded plastic house. In the investigation of optimal substrate, the eight substrate were formulated by adjusting blending rate of peatmoss, perlite, coir dust(coco peat), and vermiculite. Then, the changes in physico chemical properties of root substrates as well as their influences on the growth characteristics and yield were determined at six months after sowing. The elevation of the blending rate of peatmoss from 50% to 70% with decrease in the rate of inorganic component (mixture of perlite and vermiculite) from 50 to 30% resulted in the increase in container capacities and decrease in total porosities and air-filled capacities. The concentrations of $NH_4-N$, $P_2O_5$ and K increased as the incorporation rate of castor seed meal, phosphate ore, and langbenite, respectively, were elevated during the root medium formulations. The PPV-1 and PPV-4 substrates produced high stem length, stem diameter, shoot fresh weight, leaf area and root length among eight substrate. Root fresh weight was heaviest in PPV-4 compound nursery media. The results of this experiment will be utilized in the new substrate application for ginseng organic culture in shaded vinyl house.

• Journal of Microbiology
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• v.40 no.4
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• pp.305-312
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• 2002

The effects of two natural polyamines (putrescine and spermidine) on the synthesis of ArcA, a response regulator of the Arc two-component signal transduction system, were studied using an E. coli mutant deficient in polyamine biosynthesis. Endogenous polyamine deficiency of the mutant resulted in marked reduction in the ArcA level determined by Western blot analysis. Putrescine supplement to the growth medium effectively increased the ArcA level of the mutant in a concentration-dependent manner. Spermidine also stimulated the ArcA level in the mutant to a greater degree than putrescine. Expression of arcA'::lacZ operon fusion in the mutant was stimulated 6-fold and 10-fold by putrescine and spermidine at a 1mM concentration, respectively, indicating that the stimulatory effect of the polyamines on ArcA synthesis is due to transcriptional induction, and that spermidine is a more potent arcA inducer than putrescine. The polyamine-dependent arcA'::lacZ induction was growth-phase-dependent and independent of either arcA or fnr which are two regulators involved in anaerobic stimulation of the Arch level. These results suggested that putrescine and spermidine polyamines may be potential intracellular signal molecules in the control of arcA expression, and thereby may play an important role in cellular metabolism.

• Journal of Nutrition and Health
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• v.34 no.2
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• pp.150-157
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• 2001

Intestinal absorption of dietary taurine is one of the regulatory component maintaining taurine homeostasis along with renal reabsorption, bile acid conjugation and secretion, and de nobo synthesis of taurine in mammals. Recent observations of decreased enterocytic levels of taurine in response to trauma, infection and surgical insults, postulate the possibility that intestinal taurine absorption might be impaired in such stressed conditions. The aim of the present study was to evaluate changes in enterocytic taurine transporter activity using the human intestinal colon carcinoma cell line, HT-29, in various stress-induced conditions. Pretreatment of the HT-29 cells with dexamethasone, a stress hormone(0.1,1,10 or 100$\mu$M) for 3 hrs, or with E coli heat-stable enterotoxin(10, 100, or 200nM) for 30 minutes in order to induce the condition of enterotoxigenic infection did not influence taurine uptake as compared to the value found in control cells. In contrast, pretreatment of the cells with cholera toxin(10, 100, 500, or 1000ng/ml)for 3hr or 24hr significantly decreased taurine uptake by HT-29 cells to 40~50% of the value found in untreated control cells. Kinetic studies of the taurine transporter activity were conducted in control and cholera toxin treated HT-29 cells with varying taurine concentrations(2~60$\mu$M) in the uptake medium. Pretreatment of the cells with cholera toxin(100ng/ml) for 3hr did not influence the Vmax, but resulted in a 55% increase in the Michaelis-Menten constant(Km) of the taurine transporter compared to those in control cells. These results suggest that cholera toxin-induced reduction in taurine transporter activity in HT-29 cells is associated with decreased affinity of the taurine transporter without altering the amount of transporter protein. Intestinal taurine absorption appears to be reduced in the condition of water-borne diseases caused by bacteria such as V. cholerae. This might influence the taurine status of infants and young children more readily, an age group in which the prevalence of intestinal infection is high and the role of intestinal absorption is crucial for maintaining the body taurine pool. (Korean J Nutrition 34(2) : 150-157, 2001)