• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.2
• /
• pp.50.2-50.2
• /
• 2016

Polarization is a rich source of information on the physical properties of astronomical objects. In particular, scattered sunlight by optically thin media (e.g., cometary comae) shows linear polarization of light, which highly depends on the phase angle (an angle between the Sun-Comet-Earth), wavelengths, and physical properties of cometary dust particles such as size, composition, and structures. Here, we present a study of polarimetric properties of non-periodic comet C/2013 US10 (Catalina) in optical and near-infrared wavelength regions obtained from imaging, spectroscopy, and polarimetric observations taken on UT 2015 December 17 - 19 welcoming its (probably) first close approach to the Earth. In this presentation, we want to introduce our progress since the last Korean Astronomical Society meeting (at BEXCO, Busan, 2016 April 14 - 15) especially in terms of spatial variations of degree of linear polarization (DOLP) and its possible scenarios to explain the correlations with other observational results. In particular, we found that there is strong anti-correlation between the gas/dust flux ratio and DOLP at the cometocentric distance of $(2-5){\times}104 km$. Besides, within 10 arcseconds in radii (corresponding to inner coma region of 104 km from the center), the inverse relationship of these two parameters does not hold anymore. We conjecture that the rapid outward increase of DOLP can be supported by either the sublimation/evaporation of icy volatiles, disaggregation of cometary dust particles ejected from the nucleus, and/or difference of dominant dust particle sizes. From our results, we can conclude that comet C/2013 US10 (Catalina) corroborates rather indefinite traditional classification of poalrimetric classes of comets, and provides good opportunity to study less processed material which probably cherishes its memory at the formation epoch of the Solar System.

• Molecules and Cells
• /
• v.27 no.3
• /
• pp.291-297
• /
• 2009

Apolipoprotein (apo) C-III is a marker protein of triacylglycerol (TG)-rich lipoproteins and high-density lipoproteins (HDL), and has been proposed as a risk factor of coronary heart disease. To compare the physiologic role of reconstituted HDL (rHDL) with or without apoC-III, we synthesized rHDL with molar ratios of apoA-I:apoC-III of 1:0, 1:0.5, 1:1, and 1:2. Increasing the apoC-III content in rHDL produced smaller rHDL particles with a lower number of apoA-I molecules. Furthermore, increasing the molar ratio of apoC-III in rHDL enhanced the surfactant-like properties and the ability to lyse dimyristoyl phosphatidylcholine. Furthermore, rHDL containing apoC-III was found to be more resistant to particle rearrangement in the presence of low-density lipoprotein (LDL) than rHDL that contained apoA-I alone. In addition, the lecithin:cholesterol acyltransferase (LCAT) activation ability was reduced as the apoC-III content of the rHDL increased; however, the CE transfer ability was not decreased by the increase of apoC-III. Finally, rHDL containing apoC-III aggravated the production of MDA in cell culture media, which led to increased cellular uptake of LDL. Thus, the addition of apoC-III to rHDL induced changes in the structural and functional properties of the rHDL, especially in particle size and rearrangement and LCAT activation. These alterations may lead to beneficial functions of HDL, which is involved in anti-atherogenic properties in the circulation.

• Journal of Life Science
• /
• v.18 no.11
• /
• pp.1479-1484
• /
• 2008

Deep seawater (DSW) refers to water extracted from the ocean, usually at depths of 200 meters or more, which is rich in inorganic materials and has attracted attention for various applications. We investigated the effects of the DSW on the synaptic maturation of cultured rat hippocampal neurons. Immunocytochemical examination of DIV21 showed that PSD-95, $\alpha$CaMKII, and synGAP$\alpha1$clusters were strengthened and coupling rates of SV2 and NR2B were significantly increased in neurons grown in the presence of H-800 and H-1000 DSW. Our results indicate that DSW promotes the formation of excitatory postsynaptic signal transduction complexes NRC/MASC and functional synapses.

• The Plant Pathology Journal
• /
• v.28 no.1
• /
• pp.68-74
• /
• 2012

Biocontrol microbes have mainly been screened among large collections of microorganisms $via.$ nutrient-rich $in$ $vitro$ assays to identify novel and effective isolates. However, thus far, isolates from only a few genera, mainly spore-forming bacilli, have been commercially developed. In order to isolate field-effective biocontrol microbes, we screened for more than 200 oligotrophic bacterial strains, isolated from rhizospheres of various soil samples in Korea, which induced systemic resistance against the soft-rot disease caused by $Pectobacterium$ $carotovorum$ SCC1; we subsequently conducted in $planta$ bioassay screening. Two oligotrophic bacterial strains were selected for induced systemic disease resistance against the $Tobacco$ $Mosaic$ $Virus$ and the gray mold disease caused by $Botrytis$ $cinerea$. The oligotrophic bacterial strains were identified as $Pseudomonas$ $manteilii$ B001 and $Bacillus$ $cereus$ C003 by biochemical analysis and the phylogenetic analysis of the 16S rRNA sequence. These bacterial strains did not exhibit any antifungal activities against plant pathogenic fungi but evidenced several other beneficial biocontrol traits, including phosphate solubilization and gelatin utilization. Collectively, our results indicate that the isolated oligotrophic bacterial strains possessing induced systemic disease resistance could provide useful tools as effective biopesticides and might be successfully used as cost-effective and preventive biocontrol agents in the field.

• The Journal of the Korea Contents Association
• /
• v.11 no.2
• /
• pp.259-267
• /
• 2011

Although having only become a unified nation in latter 19th century, Germany saw a movement centered on intellectuals to find culture via mental revolution after experiencing much confusion amidst rapid urbanization and materialism. Having expressed as they are such psychological states as anger, sorrow, repression, etc., which arise in reality, by remaining faithful to instinctive sensibility, the form naturally becomes distorted or exaggerated and continues on the tradition of romanticism of a powerful, dark, and introverted atmosphere. Having been discontinued after being branded as 'decadent art' by the Nazis of Fascism, expressionist art has returned in latter 20th century mainly centered on Germany, and this merits our attention. While neo expressionists actively use various objets and media, they metaphorically express hope about Germany's culture and society by again placing on the screen figures, myths, and symbols using rough brush touch, rich colors, etc., which past expressionists enjoyed using to represent the inner world of humans. As such, by examining expressionism, which can be seen as the origin of neo expressionism, we will discover the context in which these people conform to Germany's traditional romanticism and how they inherited and developed it.

• The Journal of Pediatrics of Korean Medicine
• /
• v.14 no.2
• /
• pp.105-120
• /
• 2000

Clinical studies were done treated with aroma-therapy in 17cases of patients for suffering sinusitis, who were treated at Dept. of Pediatrics in the Hospital of Daejon from March 2000 to November 2000. The results were as follows. 1. In distribution of sex & age, 70.6% was men and 29.4% women. 47.1% was between 5 and 7 years old, 35.3% within 5 years old. 2. In distribution of the period of the clinical history, 35.3% was over 6 momths, 29.4% of them between 6 and 12 months. 3. In the living environment the apartment was 58.5% and the residental zone is 29.4%. 4. The incurrence of season is winter, 47.0% next is change of season, 29.4%. 5. At night the symptom is the most common, 52.9%. In the morning is the next, 35.3%. 6. In the past history. tinnitus was the best at 38.4%. The otitis media. atopic dermatitis, convulsion disease is next at 15.4%. 7. In the family history. the allergic rhinitis or sinusitis is the most rich at 38.4% and tinnitus is next at 23.0%. 8. In distribution of the chief complain companied with sinusitis, 23.3% was nasal obstruction, each 18.4% of them nasal discharge, cough. 9. In distribution of the duration of therapy, 29.4% was over 6 months, 23.5% between 5-6 months. In distribution of the therapeutic method, 47.1% was treated with western and oriental medicine and 42.1% only oriental medical care. 10. In distribution of the period of improvement of symptom(by X-ray reading), 35.2% was between 2-3 momths, 29.4% between 1-2 months. 11. In emotional change, after aroma-therapy, 82.4% of them felt good. 12. After treatment, 70.6% was excellent, 17.6% was good.

• Journal of Life Science
• /
• v.18 no.6
• /
• pp.897-901
• /
• 2008

Deep seawater (DSW; deep ocean water) is pure, rich in inorganic materials which have attracted attention for various applications. In this study we investigated the effects of the DSW upwelled from the East Sea, offshore Yang Yang (Korea) on the morphological differentiation of cultured rat hippocampal neurons, which were grown in the minimal essential medium containing 10% (v/v) fetal bovine serum and 25% (v/v) DSW with various hardness. DSW had no effect on initial morphological differentiation (17 hr post-plating). When observed on DIV3, 7, 14, and 17, low hardness (0 and 200) DSW reduced dendritic branching. However, dendritic branches within $80\;{\mu}m$ diameter from the center of soma nearly doubled in neurons grown in hardness 1,000 DSW-containing media. DSW with hardness 600 was more or less same as control groups. These results indicate that DSW with appropriate hardness ameliorates neuronal health.

• Journal of the Korean Society of Food Culture
• /
• v.13 no.2
• /
• pp.107-118
• /
• 1998

A nutrition education program for teachers and caregivers of the preschool children can be most effective when it is based on a comprehensive needs assessment dealing with sociodemographic factors, dietary habits, and nutrition. The purpose of the present study was to investigate current dietary habits and nutrition knowledge of the teachers and caregivers of the day-care centers. Two hundred forty two teachers and caregivers were administered a questionnaire which was designed to ascertain informations on sociodemographic data, dietary habits and nutrition knowledge. Dietary habits of the teachers were found to be significantly different by sociodemographic variables; breakfast skipping/meal irregularities (age, p=0.011); frequency of snacking (education level p=0.031); preference for salty taste(age, p = 0.000, marital status p=0.038); preference for sweet tarte (age p=0.009); preference for vegetables (income level p=0.050); frequency of eating out (age p=0.028, marital status p=0.001); frequency of coffee drinking (age p=0.019). Daycare center teachers' nutrition knowledge level was found to be less than adequate expecially on nutrients that are liable to be deficient in young growing children and their food sources. Proportions of the teachers who answered correctly to the questions on foods rich in vitamin A, iron content of milk, bioavailability of calcium in plant foods were as low as 20.2%-54.5%. The most frequently used sources of nutrition information were mass media such as TV, radio, newspaper and magazines. Only 2.9% of the subjects reported that they obtain nutrition information from health professionals such as nutritionists/dietitians, physicians, and nurses. These findings are applicable at the planning and implementation stages of various nutrition programs for the improvement of dietary habits and nutrition knowledge of the teachers and caregivers of the daycare centers. Further studies are needed to investigate the effects of teachers' dietary of habits and nutrition knowledge on food habits of young growing children.

• Korean Journal of Environmental Biology
• /
• v.37 no.4
• /
• pp.526-534
• /
• 2019

Chlorella gloriosa (Chlorellaceae, Trebouxiophyceae) was isolated from seawater off the coast of the Dokdo Islands in Korea. An axenic culture was established using the streak-plate method on f/2 agar media supplemented with antibiotics, allowing identification of the isolate by morphological, molecular, and physiological analyses. The morphological characteristics observed by light and electron microscopy revealed typical morphologies of C. gloriosa species. The molecular phylogenetic inference drawn from the small-subunit 18S rRNA sequence verified that the microalgal strain belongs to C. gloriosa. Additionally, gas chromatography-mass spectrometry analysis showed that the isolate was rich in nutritionally important omega-3 and -6 polyunsaturated fatty acids and high-performance liquid chromatography analysis revealed that the high-value antioxidants lutein and violaxanthin were biosynthesized as accessory pigments by this microalga, with arabinose, galactose, and glucose as the major monosaccharides. Therefore, in this study, a Korean marine C. gloriosa species was discovered, characterized, and described, and subsequently added to the national culture collection.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.2
• /
• pp.326-336
• /
• 2016

Saccharomyces cerevisiae is one of the most employed cell factories for the production of bioproducts. Although monomeric hexose sugars constitute the preferential carbon source, this yeast can grow on a wide variety of nitrogen sources that are catabolized through central nitrogen metabolism (CNM). To evaluate the effects of internal perturbations on nitrogen utilization, we characterized strains deleted or overexpressed in GLT1, encoding for one of the key enzymes of the CNM node, the glutamate synthase. These strains, together with the parental strain as control, have been cultivated in minimal medium formulated with ammonium sulfate, glutamate, or glutamine as nitrogen source. Growth kinetics, together with the determination of protein content, viability, and reactive oxygen species (ROS) accumulation at the single cell level, revealed that GLT1 modulations do not significantly influence the cellular physiology, whereas the nitrogen source does. As important exceptions, GLT1 deletion negatively affected the scavenging activity of glutamate against ROS accumulation, when cells were treated with H₂O₂, whereas Glt1p overproduction led to lower viability in glutamine medium. Overall, this confirms the robustness of the CNM node against internal perturbations, but, at the same time, highlights its plasticity in respect to the environment. Considering that side-stream protein-rich waste materials are emerging as substrates to be used in an integrated biorefinery, these results underline the importance of preliminarily evaluating the best nitrogen source not only for media formulation, but also for the overall economics of the process.