• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.651-660
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• 2006

Natural products are a rich source of biologically active small molecules and a fertile area for lead discovery of new drugs [10, 52]. For instance, 5% of the 1,031 new chemical entities approved as drugs by the US Food and Drug Administration (FDA) were natural products between 1981 and 2002, and another 23% were natural product-derived molecules [53]. These molecules have evolved through millions of years of natural selection to interact with biomolecules in the cells or organisms and offer unrivaled chemical and structural diversity [14, 37]. Nonetheless, a large percentage of nature remains unexplored, in particular, in the marine and microbial environments. Therefore, natural products are still major valuable sources of innovative therapeutic agents for human diseases. However, even when a natural product is found to exhibit biological activity, the cellular target and mode of action of the compound are mostly mysterious. This is also true of many natural products that are currently under clinical trials or have already been approved as clinical drugs [11]. The lack of information on a definitive cellular target for a biologically active natural product prevents the rational design and development of more potent therapeutics. Therefore, there is a great need for new techniques to expedite the rapid identification and validation of cellular targets for biologically active natural products. Chemical genomics is a new integrated research engine toward functional studies of genome and drug discovery [40, 69]. The identification and validation of cellular receptors of biologically active small molecules is one of the key goals of the discipline. This eventually facilitates subsequent rational drug design, and provides valuable information on the receptors in cellular processes. Indeed, several biologically crucial proteins have already been identified as targets for natural products using chemical genomics approach (Table 1). Herein, the representative case studies of chemical genomics using natural products derived from microbes, marine sources, and plants will be introduced.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.15-29
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• 1999

The purpose of this study is to investigate various mathematics education improvement or reform movements of Western Europe countries (United Kingdom, Germany, etc.) and the United States of America, to see the effects of those movements on Korean mathematics education circle, and to find a direction of Korean mathematics curriculum design. The third Korean mathematics curriculum was most affected by the new mathematics movement of the United States of America. This movement was emphasizing abstract structure, logical rigorousness and discovery learning of mathematics, which was fired from late fifties. Korean mathematics education circle imported the new mathematics early seventies from USA, but serious problems had been found at that time in USA. This study has pointed out that new math oriented Korean mathematics curriculum was not proper and the new mathematics itself was disastrous for most Korean students' learning. The study also points out that they hurried too much introducing the new mathematics and publishing new mathematics oriented textbooks but they had not sufficient teacher training programs. In our future mathematics curriculum reform, we have to remember such a historical lesson.

• Management & Information Systems Review
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• v.32 no.4
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• pp.189-207
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• 2013

Using high-frequency data for 2 years, this study investigates intraday lead-lag relationship between stock index and stock index futures markets in Korea and China. We found that there are some differences in price discovery and volatility transmission between Korea and China after the stock index futures markets was introduced. Following Stoll-Whaley(1990) and Chan(1992), the multiple regression is estimated to examine the lead-lag patterns between the two markets by Newey-West's(1987) heteroskedasticity and autocorrelation consistent covariance matrix(HAC matrix). Empirical results of KOSPI 200 shows that the futures market leads the cash market and weak evidence that the cash market leads the futures market. New market information disseminates in the futures market before the stock market with index arbitrageurs then stepping in quickly to bring the cost-of-carry relation back into alignment. The regression tests for the conditional volatility which is estimated using EGARCH model do not show that there is a clear pattern of the futures market leading the stock market in terms of the volatility even though controlling nonsynchronous trading effects. This implies that information in price innovations that originate in the futures market is transmitted to the volatility of the cash market. Empirical results of CSI 300 shows that the cash market is found to play a more dominant role in the price discovery process after the Chinese index started a sharp decline immediately after the stock index futures were introduced. The new stock index futures markets does not function well in its price discovery performance at its infancy stage, apparently due to high barriers to entry into this emerging futures markets. Based on EGAECH model, the results uncover strong bi-directional dependence in the intraday volatility of both markets.

• Animal cells and systems
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• v.8 no.3
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• pp.155-163
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• 2004

Tenuidraconema koreensis, a new species of free-living marine nematodes, collected from the subtidal coarse sediments and various invertebrates of Namae, is described. The new species differs from T. fiersi Decraemer, 1989, the only other species in the genus, by having the combination of the following characters: the position of twelve cephalic adhesion tubes in both sexes (anterior six cephalic adhesion tubes inserted on the rostrum and posterior six inserted on the body annules), and the number of posterior sublateral adhesion tubes (12 in male and 13 in female) and posterior subventral adhesion tubes (15 in male and 19 in female). This paper contains the description of the new species with illustrations and scanning electron microscope (SEM) photomicrographs. This is the first discovery of the monotypic genus Tenuidraconema outside the type locality.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.5
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• pp.650-657
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• 2018

Objective: The study investigated the biological functions and mechanisms for controlling cashmere growth of Liaoning cashmere goat by ovarian carcinoma immunoreactive antigen-like protein 2 (OCIAD2) and decorin (DCN) genes. Methods: cDNA library of Liaoning cashmere goat was constructed in early stages. OCIAD2 and DCN genes related to cashmere growth were identified by homology analysis comparison. The expression location of OCIAD2 and DCN genes in primary and secondary hair follicles (SF) was performed using in situ hybridization. The expression of OCIAD2 and DCN genes in primary and SF was performed using real-time polymerase chain reaction (PCR). Results: In situ hybridization revealed that OCIAD2 and DCN were expressed in the inner root sheath of Liaoning cashmere goat hair follicles. Real-time quantitative PCR showed that these genes were highly expressed in SF during anagen, while these genes were highly expressed in primary hair follicle in catagen phase. Melatonin (MT) inhibited the expression of OCIAD2 and promoted the expression of DCN. Insulin-like growth factors-1 (IGF-1) inhibited the expression of OCIAD2 and DCN, while fibroblast growth factors 5 (FGF5) promoted the expression of these genes. MT and IGF-1 promoted OCIAD2 synergistically, while MT and FGF5 inhibited the genes simultaneously. MT+IGF-1/MT+FGF5 inhibited DCN gene. RNAi technology showed that OCIAD2 expression was promoted, while that of DCN was inhibited. Conclusion: Activation of bone morphogenetic protein (BMP) signaling pathway up-regulated OCIAD2 expression and stimulated SF to control cell proliferation. DCN gene affected hair follicle morphogenesis and periodic changes by promoting transforming growth $factor-{\beta}$ ($TGF-{\beta}$) and BMP signaling pathways. OCIAD2 and DCN genes have opposite effects on $TGF-{\beta}$ signaling pathway and inhibit each other to affect the hair growth.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.1
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• pp.42-50
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• 2008

Unlike a cellular network, a mobile ad hoc network(MANET) is constructed only by mobile nodes without access point. Mobile nodes in MANET operate with scarce resources and restricted battery. If battery of intermediate node is exhausted, overall network might be diverged. Therefore, power-aware is really important. An on-demand multipath routing protocol which is proposed to compensate for shortcoming of on-demand single path routing protocol can reduce mute discovery overhead because route discovery starts only when all routes are disconnected. AOMDV(Ad hoc On-demand Multipath Distance Vector) which is on-demand multipath routing protocol based on AODV, reduces 40% of route discovery frequency. However, AOMDV have none of power-aware. So AOMDV have problem that route discovery for power exhaustion is not reduced at all. This paper proposes new power-aware path selection algorithm for AOMDV and scheme that broadcast REER packets when mobile node's battery can be gone. Performance comparison of proposed algorithm with AOMDV using ns-2 simulator shows that route discovery of proposed algorithm is reduced maximally 36.57% than AOMDV's.

• Journal of Integrative Natural Science
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• v.3 no.3
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• pp.162-167
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• 2010

A pseudoreceptor combines structure-based and ligand-based techniques to represent a unifying concept for both receptor mapping and ligand matching. In this molecular modeling approach, there are opportunities to construct the pseudoreceptor models using a set of small molecules. To build a reliable pseudoreceptor model, we need a set of ligand molecules with known affinity (biological activity) to generate 3D bioactive conformation for each of these ligand molecules. Several software packages are available to generate a pseudoreceptor model and this can provide an entry point for structure based drug discovery in cases where receptor structure information is not available. In this review, we presented the concept of pseudoreceptor, as well as discussed about various software packages available to generate a pseudoreceptor model.

• Journal of the speleological society of Korea
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• no.4
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• pp.69-78
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• 1996

During the year and a half of preparation for the Untnmed Ri Expedition (Caves $ Caving 29 p. 29) a lot of time was devoted developing the techniques we would use to explore the roaring wh waters of Nare. We finally left for New Britain with a whole new set caving rules and hardware which would not be out of place in an Indi Jones movie. The first serious work to tackle this new problem in caving wa pioneered by the French in 1978 after the discovery of the Nare. M and Kavakuna - all big river caves with flows of 15-20 cumes. We tir out these techniques on the white water rivers of north Wales. ma some improvements and tested some new ideas. This articles is a summary of our research and experience.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.58.1-58.1
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• 2012

We present a comprehensive re-analysis of stellar photometric variability in the field of open cluster M37, using our new high-precision light curves. This dataset provides a rare opportunity to explore different types of variability between short (-minutes) and long (-one month) time-scales. To investigate the variability properties of -30,000 objects, we developed new algorithms for detecting periodic, aperiodic, and sporadic variability in their light curves. About 7.5% (2,284) of the total sample exhibits convincing variations that are induced by flares, pulsations, eclipses, starspots and, in some cases, unknown causes. The benefits of our new photometry and analysis package are evident. The discovery rate of new variables is increased by 63% in comparison with the existing catalog of variables, and 51 previously identified variables were found to be false positives resulting from time-dependent systematic effects. Based on extended and improved catalog of variables, we will review the basic properties (e.g., periodicity, amplitude, type) of the variability and how different they are for different spectral types and for cluster memberships.

• ALGAE
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• v.31 no.4
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• pp.341-349
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• 2016

The red algal genus Amalthea was first described from New Zealand with one species, A. freemaniae. We discovered a new species of Amalthea from Korea, Amalthea rubida sp. nov., and described it based on morphology and rbcL sequences. A. rubida is characterized by a foliose, membranous and soft thallus having loosely arranged anticlinal medullary filaments, much like A. freemaniae, except for a difference of the cortex thickness in the basal part of vegetative structure. In the rbcL phylogenetic analyses, A. rubida formed a clade with A. freemaniae from New Zealand and Halymenia abyssicola from Mexico. A. rubida showed 5.7% interspecific divergence to A. freemaniae and 4.7% to H. abyssicola. Our discovery of A. rubida expands the distribution of Amalthea from the oceanic southwestern Pacific into the continental northwestern. A targeted global study is needed to fully reveal the species diversity and phylogenetic relationships of the genus Amalthea and members of the order Halymeniales.