• Korean Journal of Ecology and Environment
• /
• v.49 no.1
• /
• pp.11-21
• /
• 2016

Cymbidium kanran Makino is being threatened in its own habitats due illegal collecting and habitat changes by vegetation growth along historical landuse change. In this study, we established habitat restoration model for conservation of C. kanran based on ecological diagnosis. Through exploration to Jeju Island in 2014 and 2015, we identified 27 unknown habitats of C. kanran and in there, abiotic variables and vegetation structure and composition were quantified. Altitudinal distribution of C. kanran was between 200 m~700 m a.s.l. and compared to distribution in 2004, Area of Occupation (AOO) decreased at 82%. Specific habitat affinity was not observed by evenly found in mountain slope and valley and summergreen and evergreen broadleaved forests, but likely more abundant in valley habitats with higher soil and ambient moisture. Total of 96 individual of C. kanran was observed with an average density of $942.6individuals\;ha^{-1}$. The plants showed relatively short leaf length (average=$10.7cm{\pm}1.1cm$) and small number of pseudo bulbs ($1.2{\pm}0.2$). Flowering and fruiting individuals were not observed in field. C. kanran was classified into endangered plant species as CR (Critically Endangered) category by IUCN criteria. Phenotypic plasticity of C. kanran was likely support to sustain in more shaded habitat environment and recent habatat changes to closed canopy and low light availability may exhibit negatively effects to C. kanran's life history. Restoring C. kanran habitat should create open environment as grassland and low woody species density.

• Korean Journal of Soil Science and Fertilizer
• /
• v.6 no.2
• /
• pp.115-127
• /
• 1973

Leaf discoloration of IR667 lines (tropical) and leading locals (temperate) in fields was classified according to the probable causes and nutritional disorder due to soil reduction in 1972 was investigated. 1. The causes of leaf discoloration in IR667 were low air temperature, soil reduction, seed born, insect bite, nitrogen depression, overdose pesticide, strong wind, early senescence and unknown one. 2. Leaf discoloration due to soil reduction which has been called Sageumbyeong by famers, was caused by the heavy application of $Ca(OH)_2$, compost and poor drainage followed by Zn and K deficiency and Fe toxicity. 3. About 30 days after transplanting deficiency concentration of K and Zn in leaf blade appears to be less than 2.0% and 20ppm respectively, and greater than 200ppm, 500ppm, and 1.0% respectively for toxicity or excess of Fe, Mn and Ca. and in the shoot 2.4% for K, 30ppm for Zn and 800ppm for Fe. The value of K/Ca should be greaterthan 2.0 for health. 4. When plants were damaged by soil reduction the contents of N, P, Ca, Mg, Fe, Mn, Na in shoot were increased and those of K, Zn, Si were decreased. 5. IR667 lines show in shoot higher content of N, P, Ca, Mg, Si, Na, and lower content K, Zn, Fe, Mn and lower root activity than local leading varietles in either healthy or disieased case, indicating IR667 lines are likely more suseptible to soil reduction damage. 6. Normal soil was less than 6.5 of pH and greater than -50 mv of Eh, but pH of problem soil was ranged from 6.7 to 7.4 and Eh from -100 to -190. 7. The root activity (${\alpha}$-naphthylamine oxidation) decreased at early stage of soil redudtion damage, then increased with severity and at the end it decreased again, but IR667 lines showed always lower root activity than local ones.

• Journal of Space Technology and Applications
• /
• v.1 no.3
• /
• pp.283-301
• /
• 2021

In order to satisfy the intellectual curiosity of mankind to explore the unknown, National Aeronautics and Space Administration (NASA) in the United States and European Space Agency (ESA) in Europe are embarking on various R&D under the motto of the grand dream of pioneering space into a safe and sustainable environment. In the 2020s and 30s, it is expected that advanced giant observation equipment will be in operation, such as the development of a 10-meter-class telescope in space. In Korea, following the development of the 0.15 m Near-Infrared Imaging Spectrometer (NISS), Korea Astronomy and Space Science Institute (KASI) is also participating a 0.2 m Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx) as an international cooperation partner in small exploration telescope. However, domestic experience in the development and operation of the space telescopes is still insufficient, and there is no plan with long-term prospects for constructing telescopes. In order to answer questions about the unknown world that mankind has not experienced using our own equipment, planning and preparation for the construction of a space telescope through close cooperation among industry-university-institute-government is urgently needed. In this paper, the necessity, background, development goals, and expected effects of the development of the Korean Space Telescope are summarized conceptually, and a working group (WG) is also proposed. In the WG activities, Korea shall take the lead in establishing the Korean-style space telescope development plan, and will start a valuable step to establish the national direction in the field of space astronomy and related technologies. We hope that the WG will be another milestone in Korea's space development.

• Economic and Environmental Geology
• /
• v.50 no.6
• /
• pp.445-466
• /
• 2017

Yeongdong area is located in the contact zone between central southeastern Ogcheon belt and Yeongnam massif, in which Cretaceous Yeongdong basin exists. Therefore, the study area has complex geological environment of various geological age and rock types such as Precambrian metamorphic rocks, age-unknown Ogcheon Supergroup, Paleozoic/Mesozoic sedimentary rocks, Mesozoic igneous rocks and Quaternary alluvial deposits. This study focuses on the link between the various geology and water type, and discussed the source of some major ions and their related water-rock interaction. For this study, the field parameters and ion concentrations for twenty alluvial/weathered and eighty bedrock aquifer wells were used. Statistical analysis indicates that there was no significant differences in groundwater quality between wet and dry seasons. Although various types were observed due to complex geology, 80 to 84 % of samples showed $Ca-HCO_3$ water type. Some wells placed in alluvial/weathered aquifers of Precambrian metamorphic and Jurassic granitic terrains showed somewhat elevated $NO_3$ and Cl concentrations. $Mg-HCO_3$ typed waters prevailed in Cretaceous Yeongdong sedimentary rocks. The deeper wells placed in bedrock aquifers showed complicated water types varying from $Ca-HCO_3$ through $Ca-Cl/SO_4/NO_3$ to $Na-HCO_3$ and Na-Cl type. Groundwater samples with $Na-HCO_3$ or Na-Cl types are generally high in F concentrations, indicating more influences of water-rock interaction within mineralized/hydrothermal alteration zone by Cretaceous porphyry or granites. This study revealed that many deep-seated aquifer had been contaminated by $NO_3$, especially prominent in Jurassic granites area. Based on molar ratios of $HCO_3/Ca$, $HCO_3/Na$, Na/Si, it can be inferred that Ca and $HCO_3$ components of most groundwater in alluvial/weathered aquifer wells were definitely related with dissolution of calcite. On the other hand, Ca and $HCO_3$ in bedrock aquifer seem to be due to dissolution of feldspar besides calcite. However, these molar ratios require other mechanism except simple weathering process causing feldspar to be broken into kaolinite. The origin of $HCO_3$ of some groundwater occurring in Cretaceous Yeongdong sedimentary rock area seems to be from dissolution of dolomite($MgCO_3$) or strontianite($SrCO_3$) as well.

• Korean Journal of Ichthyology
• /
• v.32 no.3
• /
• pp.117-129
• /
• 2020

The body color pattern in fish is a distinctive feature for species identification. The blass bloched rockfish Sebastes pachycephalus is a commercially important marine fish species, distributed in the central and southern parts of Korea and south Hokkaido of Japan. It has a morphological feature divided into four subspecies according to with or lacking distinct spots on the body surface, and to the location of markings on the body surface. However, the genetic basis of body color pattern of S. pachycephalus is still unknown. Thus we analyzed the transcriptome of S. pachycephalus skin samples using RNA-seq analysis to investigate functional genes related to body color patterns. The experimental skin samples were prepared by classified into 'Wild type' (lacking distinct spots and markings) and 'Color type' (with distinct spots and marking). Two skin sample transcriptomes were compared pairwise and the results revealed that were 164 differentially expressed unigenes in the skin samples of 'Wild type' and 'Color type'. Gene Ontology analysis of 164 differentially expressed unigenes showed that these genes were included in the functional group of molecular function (2 genes), biological process (46 genes), and cellular component (6 genes). There were several genes that body color type skin specific expression and the genes were CTL (Galactose-specific lectin nattectin), CUL1 (Cullin-1), CMAS (N-acylneuraminate cytidylyltransferase), NMRK2 (Nicotinamide riboside kinase 2), ALOXE3 (Hydroperoxide isomerase ALOXE3), SLC4A7 (sodium bicarbonate cotransporter 3). Our study is the first attempt to search for functional genes involved in the formation of body color patterns in S. pachycephalus. The differentially expressed unigenes obtained in this study can be used as candidate genes for functional gene study related to body coloration of fish.

• Korean Journal of Plant Resources
• /
• v.29 no.4
• /
• pp.467-478
• /
• 2016

This study was carried out to elucidate the distribution of vascular plants and their usefulness of Mt. Janggunbong (1,136 m) in Bonghwa-gun, Gyeoungsangbuk-do. The vascular plants, collected 15 times from 2006 to 2015, consisted a total of 462 taxa; 82 families, 279 genera, 397 species, 2 subspecies, 55 varieties, 8 forms. 10 taxa of the Korean endemic plants were recorded and 1 taxon of Critically Endangered Species (CR), 5 taxa of Vulnerable Species (VU) and 7 taxa of Least Concerned Species (LC), categorized by the Korean Forest Service as rare plants, were investigated in this region. Furthermore, Ⅳ, Ⅲ degrees of floristic regional indicator plants, designated by the Korean Ministry of Environment, were included 8 taxa and 14 taxa, respectively. Based on the usefulness, edible, pasturing, medicinal, ornamental, timber, stain, industrial, fiber and unknown usefulness plants included 352 taxa, 107 taxa, 71 taxa, 18 taxa, 8 taxa, 5 taxa, 3 taxa, 2 taxa and 111 taxa, respectively. In addition, 28 taxa of naturalized plants were observed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.6
• /
• pp.878-885
• /
• 2017

Objective: Glucose is an essential fuel in the energy metabolism and synthesis pathways of all mammalian cells. In lactating animals, glucose is the major precursor for lactose and is a substrate for the synthesis of milk proteins and fat in mammary secretory (alveolar) epithelial cells. However, clear utilization of glucose in mammary cells during lactogenesis is still unknown, due to the lack of in vitro analyzing models. Therefore, the objective of this study was to test the reliability of the mammary alveolar (MAC-T) cell as an in vitro study model for glucose metabolism and lactating system. Methods: Undifferentiated MAC-T cells were cultured in three types of Dulbecco's modified Eagle's medium with varying levels of glucose (no-glucose: 0 g/L, low-glucose: 1 g/L, and high-glucose: 4.5 g/L) for 8 d, after which differentiation to casein secretion was induced. Cell proliferation and expression levels of apoptotic genes, Insulin like growth factor-1 (IGF1) receptor, oxytocin receptor, ${\alpha}S1$, ${\alpha}S2$, and ${\beta}$ casein genes were analyzed at 1, 2, 4, and 8 d after differentiation. Results: The proliferation of MAC-T cells with high-glucose treatment was seen to be significantly higher. Expression of apoptotic genes was not affected in any group. However, expression levels of the mammary development related gene (IGF1 receptor) and lactation related gene (oxytocin receptor) were significantly higher in the low-glucose group. Expressions of ${\alpha}S1-casein$, ${\alpha}S2-casein$, and ${\beta}-casein$ were also higher in the low-glucose treated group as compared to that in the no-glucose and high-glucose groups. Conclusion: The results demonstrated that although a high-glucose environment increases cell proliferation in MAC-T cells, a low-glucose treatment to MAC-T cells induces higher expression of casein genes. Our results suggest that the MAC-T cells may be used as an in vitro model to analyze mammary cell development and lactation connected with precise biological effects.

• Molecules and Cells
• /
• v.40 no.4
• /
• pp.299-306
• /
• 2017

The transcriptional activator AphB has been implicated in acid resistance and pathogenesis in the food borne pathogens Vibrio vulnificus and Vibrio cholerae. To date, the full-length AphB crystal structure of V. cholerae has been determined and characterized by a tetrameric assembly of AphB consisting of a DNA binding domain and a regulatory domain (RD). Although acidic pH and low oxygen tension might be involved in the activation of AphB, it remains unknown which ligand or stimulus activates AphB at the molecular level. In this study, we determine the crystal structure of the AphB RD from V. vulnificus under aerobic conditions without modification at the conserved cysteine residue of the RD, even in the presence of the oxidizing agent cumene hydroperoxide. A cysteine to serine amino acid residue mutant RD protein further confirmed that the cysteine residue is not involved in sensing oxidative stress in vitro. Interestingly, an unidentified small molecule was observed in the inter-subdomain cavity in the RD when the crystal was incubated with cumene hydroperoxide molecules, suggesting a new ligand-binding site. In addition, we confirmed the role of AphB in acid tolerance by observing an aphB-dependent increase in cadC transcript level when V. vulnificus was exposed to acidic pH. Our study contributes to the understanding of the AphB molecular mechanism in the process of recognizing the host environment.

• Environmental Analysis Health and Toxicology
• /
• v.18 no.2
• /
• pp.95-100
• /
• 2003

Dichlorodiphenyltrichloroethane (DDT), is a widespread environmental pollutant. In this study, we investigated the effect of DDT on testosterone production through aromatase and investigated its molecular mechanism in testicular leydig cell, R2C. We investigated that the effects of DDT on testosterone production and its effects on aromatase activity in R2C cell by radio immunoassay (RIA). As the results, the potent leyding cell activator LH increased testosterone production compared to the control. DDT exposure significantly decreased testosterone production in R2C cell and DDT alone affected T reduction in a dose-dependent manner in R2C cell slightly. In addition, DDT was found to increase aromatase activity in R2C cell in a dose dependent manner. In order to assess whether the suppressive effects of DDT on LH-inducible testosterone production might be influenced by the ER, ICI 182.780, a pure antiestrogen, was used, and it was found that these inhibitory effects of DDT were antagonized by ICI 182.780, implying that the ER mediates the suppressive effects of DDT. Furthermore, the inducible effects of DDT on aromatase might be influenced by the ER, ICI 182.780 was used, and it was found that these enhancing effects of DDT were antagonized by ICI 182.780, implying that the ER mediates the inducible effects of DDT. Our results indicated that DDT inhibition of LH-inducible testosterone production in R2C is mediated through aromatase. However, the precise mechanisms by which DDT enhance in leyding cell remains unknown. The current study suggests the possibility that DDT might act as a modulator aromatase gene transcription.

• Journal of Life Science
• /
• v.24 no.2
• /
• pp.186-190
• /
• 2014

Carbonic anhydrase isozymes (CAs) are widespread zinc-containing metalloenzyme family. The enzyme catalyzes the reversible interconversion of $CO_2$ and $HCO_3$. This reaction is the main role of CA enzymes in physiological conditions. CA III, one of the CA isozymes, has been identified in many tissues. It is distinguished from the other isozymes by several characteristics, particularly by a lower specific activity and by its resistance to acetazolamide. However, the physiological function of CA III in fish is unknown. In this study, we examined the detection of CAs in the Shaggy sea raven Hemitripterus villosus, using SDS-PAGE, isoelectric focusing (IEF), and western blot analysis. We detected a significant protein band with molecular weight about 30 kDa from the tissues of H. villosus by SDS-PAGE and western blotting. A specific band of CA III with pI 7.0 was detected by IEF and western blotting in gill and muscle. The immunoreaction of anti-CA III expressed in the gill of H. villosus was much stronger than other tissues. One explanation for this result is that the fish gill is the only organ that is exposed to the external environment and that plays an important role in acid-base relevant ion transfer, the transfer of $H^+$ and/or $HCO{_3}^-$, for the maintenance of systemic pH. This is the first report on the identification of a carbonic anhydrase III-like protein from H. villosus.