• ALGAE
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• v.32 no.1
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• pp.29-39
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• 2017

Geographic distributions of pathogens are affected by dynamic processes involving host susceptibility, availability and abundance. An oomycete, Pythium porphyrae, is the causative agent of red rot disease, which plagues Pyropia farms in Korea and Japan almost every year and causes serious economic damage. We isolated an oomycete pathogen infecting Pyropia plicata from a natural population in Wellington, New Zealand. The pathogen was identified as Pythium porphyrae using cytochrome oxidase subunit 1 and internal transcribed spacer of the rDNA cistron molecular markers. Susceptibility test showed that this Pythium from New Zealand was able to infect several different species and genera of Bangiales including Pyropia but is not able to infect their sporophytic (conchocelis) phases. The sequences of the isolated New Zealand strain were also identical to Pythium chondricola from Korea and the type strain from the Netherlands. Genetic species delimitation analyses found no support for separating P. porphyrae from P. chondricola, nor do we find morphological characters to distinguish them. We propose that Pythium chondricola be placed in synonymy with P. porphyrae. It appears that the pathogen of Pyropia, both in aquaculture in the northern hemisphere and in natural populations in the southern hemisphere is one species.

• The Korean Journal of Mycology
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• v.22 no.3
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• pp.229-246
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• 1994

Powdery mildew fungi from 246 different species of host plants were collected at Kangwon province during 1989-1993 years. They were identified and classified into 13 genera and 83 species by examining various morphological characteristics of taxonomic value. Most of host plants were infected with one species of powdery mildew fungus, but eight plant species with two or three different mildews. Among 246 host plants collected, 43 species were added as the new host plants of powdery mildew fungi in Korea. Two Oidium spp. from Hibiscus and several Compositae plants were described to suggest their taxonomic problems.

• Journal of KIISE:Information Networking
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• v.29 no.1
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• pp.77-85
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• 2002

The surge in use of networks has recently increased demands for cryptography. Cryptography, however, can cause various problems because of difficulty of key management. A lot of researchers have been concentrating on the key recovery technique to eliminate the reverse effect of using these kinds of security and to promote positive aspects of using it. They have suggested many key recovery techniques up to the present. we propose a mechanism as a solution, which are employed to reduce the time needed to reconnect SG and the host in Host-to-Gateway in VPNs supporting IPsec, in case they are disconnected. This new mechanism using KRFSH stores information at each session in advance so that users can recall the session information when needed to rebuild the tunnel between SG and the host in a VPN. As a result, the mechanism built into SG will solve the problems above in host-to-gateway VPNs using IPsec.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.6
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• pp.463-468
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• 2012

Type 1 diabetes (T1D) is caused by dysregulation of the immune system in the pancreatic islets, which eventually leads to insulin-producing pancreatic ${\beta}$-cell death and destabilization of glucose homeostasis. One of the major characteristics of T1D pathogenesis is the production of inflammatory mediators by macrophages that result in destruction or damage of pancreatic ${\beta}$-cells. In this study the inflammatory microenvironment of T1D was simulated with RAW264.7 cells and MIN6 cells, acting as macrophages and pancreatic ${\beta}$-cells respectably. In this setting, peroxiredoxin-1, an anti-oxidant enzyme was knocked down to observe its functions in the pathogenesis of T1D. RAW264.7 cells were primed with lipopolysaccharide and co-cultured with MIN6 cells while PRX-1 was knocked down in one or both cell types. Our results suggest that hindrance of PRX-1 activity or the deficiency of this enzyme in inflammatory conditions negatively affects pancreatic ${\beta}$-cell survival. The observed decrease in viability of MIN6 cells seems to be caused by nitric oxide production. Additionally, it seems that PRX-1 affects previously reported protective activity of IL-6 in pancreatic ${\beta}$ cells as well. These results signify new, undiscovered roles for PRX-1 in inflammatory conditions and may contribute toward our understanding of autoimmunity.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.78-78
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• 2016

For the past three decades, extensive research has been performed in the surface design of new polymers for a variety of medical applications. Great progress in therapeutics and diagnostics can be attributed to these scientific advances in biomedical polymers. A variety of bioinert materials or bioactive materials using drugs, cells, and growth factors are widely utilized for the implants, devices and tissue regeneration. These materials provide an improved biocompatible materials to host, to significantly decrease or increase the host/tissue/blood response to the foreign materials. In the future, biomaterials will play a different role in modern therapeutics. New materials will be tailored to interact more on a protein and cellular level to achieve high degree of biocompatibility, biospecificity and bioacitivity. In this presentation, various biocompatible materials based on surface/bulk engineering will be demonstrated, which can be utilized as therapeutics implants and therapeutic vehicles for biologically active molecules such as cell, protein /peptide and gene.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.171-174
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• 2005

In this paper, we propose a new data encoding algorithm for a two-dimensional bar code system. In general, the one-dimensional bar code is just a key which can access detailed information to the host computer database. But the two-dimensional bar code is a new technology which can obtain high density information without access to the host computer database. We implemented the encoding algorithm for Data Matrix bar code which is the most widely used among the many kinds of two-dimensional bar codes in the field of marking using Digital Signal Processor (TMS320C31). The performance of the proposed algorithm is verified by comparing the imprinted symbols on the steel surfaces with the codes which are decoded by a bar code reader.

• Proceedings of the IEEK Conference
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• 2000.06c
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• pp.47-50
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• 2000

In this paper, we propose a new destage algorithms, called the Dynamic Adaptive Threshold which determines turn-on and turn-off thresholds dynamically depending on the current write cache occupancy level and the differential rate of the host write requests. For performance evaluation, the proposed algorithm is compared with the wellknown High-Low Water Mark (HLWM) algorithm. Performance tests are fulfilled with our cached RAID 5 simulator. The simulation results show that the proposed algorithm outperforms the HLWM algorithm in terms of response time of host reads and write cache hit ratio under various workloads.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.622-624
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• 1998

During the course of study on plant parasitic nematodes associated with medicinal herbs in Korea, high population of different stages of citrus nematode, Tylenchulus semipentrans was found in association with Pyrola japonia Klenze in Imsil, Chunbuk province. The second stage larvae and males were isolated from rhizosphere soil ; immature and mature females were detached from the roots of infested plants of Pyrola japonica. Besides citrus it has been reported to parasitize on roots of Syringa vulgaris, Diospyros lotus, olive, grapevine, and pear in different parts of the world. This is the first record of T. semipenetrans parasitized on a medicinal plant, Pyrola japonica.

• The Plant Pathology Journal
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• v.19 no.6
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• pp.274-279
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• 2003

Two Gymnosporangium species, G. japonicum and G. cornutum, causing cedar-apple rust, were newly identified in Korea, and a new aecial host for each fungus was found by artificial inoculation. Detailed descriptions of the species were made based on macroscopic features (symptoms and signs) and light and scanning electron microscopic observations of spores and peridial cells. G. japonicum from Juniperus chinensis var. horizontalis had Photinia villosa as its new aecial host G. cornutum from J. rigida showed its aecial stage on Sorbus alnifolia.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.233-239
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• 1999

To develop the potential use as new host strain for gene cloning the optimal conditions for transform-ation of alkali-tolerant Bacillus sp. were examined. The Bacillus sp. YA-14 was cultured to late logarith-mic growth phase at 37$^{\circ}C$ in modified SPI medium (pH8.0) containing 0.4% MgSO4 0.5mM CaCl2 1 ml of competent cell was mixed with 0.5$\mu$g of plasmid DNA and incubated with shaking at 37$^{\circ}C$ for 40min. The transformation frequency under the optimal condition was 4.53$\times$10-6 CFU/ml/g plasmid DNA. The electrophresis and stably maintained in the new host.