• Journal of Powder Materials
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• v.21 no.3
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• pp.215-221
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• 2014

Translucent alumina is a potential candidate for high temperature application as a replacement of the glass or polymer. Recently, due to the increasing demand of high power light emitting diode (LED), there is a growing interest in the translucent alumina. Since the translucent property is very sensitive to the internal defect, such as voids inside or abnormal grain growth of sintered alumina, it is important to fabricate the defect-free product through the fabrication process. Powder injection molding (PIM) has been commonly applied for the fabrication of complex shaped products. Among the many parameters of PIM, the flowability of powder/binder mixture becomes more significant especially for the shape of the cavity with thin thickness. Two different positions of the gate were applied during PIM using the disc type of die. The binder was removed by solvent extraction method and the brown compact was sintered at $1750^{\circ}C$ for 3 hours in a vacuum. The flowability was also simulated using moldflow (MPI 6.0) with two different types of gate. The effect of the flowability of powder/binder mixture on the microstructure of the sintered specimen was studied with the analysis of the simulation result.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.455-461
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• 1987

The ovaries or the ovules of grasses were pollinated and cultured in vitro to raise the interspecific or the intergeneric hybrids between tall fescue, meadow fescue, and Italian ryegrass. The isolated and suface-sterili-zed pistils were dusted with compatible pollens on stigma, on stump after removing stigma, or on excised ovule. Furthermore, the fertilized ovaries and ovules were cultured on MS, M6, or White's media and treated with plant growth regulators: IAA, kinetin, BA to promote embryo development and seed maturity. The in vitro fertilization in grass species ranged from 44 to 92% depending on ovary and pollen parents. The stigmatic pollination was resulted in 67.8% fertilization, the stump pollination 89.0%, and the excised ovule pollination 61.0%, repectively. White's medium was the most effective to provide embryo development and seed maturity in grass species. And the combined treatment of IAA 10mg/$\ell$, kinetin 0.2mg/$\ell$, was better than the non-treatment. Only two seedlings, one complete and one abnormal with root formation were obtained from 127 ovaryies cultured. The anatomy of ovules in vitro cultured was revealed the differentiation of vascular system and meristematic tissue, and the formation of sclerenchyma cells inside ovule.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.10
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• pp.3989-4006
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• 2020

The intelligent agriculture monitoring is based on the perception and analysis of environmental data, which enables the monitoring of the production environment and the control of environmental regulation equipment. As the scale of the application continues to expand, a large amount of data will be generated from the perception layer and uploaded to the cloud service, which will bring challenges of insufficient bandwidth and processing capacity. A fog-based offline and real-time hybrid data analysis architecture was proposed in this paper, which combines offline and real-time analysis to enable real-time data processing on resource-constrained IoT devices. Furthermore, we propose a data process-ing algorithm based on the incremental principal component analysis, which can achieve data dimensionality reduction and update of principal components. We also introduce the concept of Squared Prediction Error (SPE) value and realize the abnormal detection of data through the combination of SPE value and data fusion algorithm. To ensure the accuracy and effectiveness of the algorithm, we design a regular-SPE hybrid model update strategy, which enables the principal component to be updated on demand when data anomalies are found. In addition, this strategy can significantly reduce resource consumption growth due to the data analysis architectures. Practical datasets-based simulations have confirmed that the proposed algorithm can perform data fusion and exception processing in real-time on resource-constrained devices; Our model update strategy can reduce the overall system resource consumption while ensuring the accuracy of the algorithm.

• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.485-492
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• 2009

Estrogen has dramatic effects on the development and function of the reproductive tract in mammals. Although diethylstilbestrol (DES) triggers the development of reproductive organs in immature animals, continued exposure to DES induces dysfunction of the female reproductive tract in mice. To investigate the effects of neonatal estrogen exposure on the reproductive tract of female chickens, we implanted DES pellets into the abdominal region of immature female chicks and then examined the effects of DES on the oviducts of both immature chicks and sexually mature chickens (30 weeks old). DES induced mass growth and differentiation of the oviduct in immature chicks. The chick oviduct increased by 2.7- and 29-fold in length and weight, respectively, following primary DES stimulation. In secondary DES stimulation, the length and weight of the chick oviduct increased by 4.5- and 74-fold, respectively. Additionally, DES treatments caused abnormal development of the infundibulum and magnum in hen oviducts. Furthermore, infundibulum abnormality gave rise to unusual ovulation of follicles and resulted in infertility and dysfunction of the magnum, such as less production of egg white proteins. Our results indicate that DES exposure during early developmental stages in chickens has detrimental effects on the development and maintenance of the female reproductive tract after sexual maturation.

• Journal of Life Science
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• v.16 no.6
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• pp.1044-1051
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• 2006

The barren ground is an abnormal phenomenon of coastal ecosystem in which seaweeds, are destroyed and mostly replaced by the coralline algae containing the calcium carbonate components. To restore the seaweed forest, We have exerted an effort in the local areas, Samchuck, Korea, where barren phenomena are profound. Two methods of seaweed forest construction developed in the present study are underwater longline and seed transplantation for the brown seaweed Costaria costata, a fast growing edible seaweed. The sizes of C. costata attached on the underwater longline were $96.7{\pm}2.2mm$ of blade length and $83.6{\pm}7.7g$ of blade weight in April. Thereafter the sizes declined from May. Similar pattern was obtained from in the transplantation method with maxima of $90.4{\pm}15.8mm$ and $70.1{\pm}31.7g$ for blade length and weight, respectively in April. It appeared totality maturation from two methods in May. This maturation time is the same like that of wild C. costata.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.4
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• pp.305-310
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• 2006

Abnormal activation of the Wnt/${\beta}$-catenin pathway and subsequent up-regulation of ${\beta}$-catenin response transcription (CRT) are associated with the development of colon cancer. Thus, the Wnt/${\beta}$-catenin pathway is an attractive target for chemoprevention and treatment of this cancer. In this study, we used a cell-based screen to identify a methanol extract of Dictyota dichotoma (EDD) that suppresses the Wnt/${\beta}$-catenin pathway without altering the level of ${\beta}$-catenin protein and reduces the expression of cyclin D1, which is a known ${\beta}$-catenin/T cell factor (TCF)-dependent gene. EDD inhibited the growth of various colon cancer cells. Our findings suggest that EDD can potentially be used as a chemopreventive agent against colon cancer.

• Journal of Plant Biology
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• v.37 no.3
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• pp.309-316
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• 1994

To make regional comparisons of water status of pitch pine, the temporal changes of water status in pitch pine were investigated at different areas; urban Seoul (heavily polluted area), surburb of Seoul (lightly polluted area), and rural area (control). The effects of air pollutants, acid rain and chemical properties of soil on water deficit in pitch pine were also investiaged. Water content of needles growing at polluted areas were usually lower than that at unpolluted area. Water saturation deficit of needles growing at polluted areas were usually higher than that at unpolluted area especially in dry season. These results indicated that water in needles growing at polluted areas were usually more deficient than that at unpolluted area, and were more deficient in April than other months. At polluted areas, the older the needles were, the more quickly transpirated the water in the needle was. At unpolluted areas, however, water in old needles was not so quickly transpirated as those at polluted areas. Water potential of needles of pitch pine seedlings treated with simulated acid rain (SAR) of pH 3.5 decreased more quickly than that of needles treated with SAR of pH 5.6. Loss of water through epicuticular layer was greater in the following order: magnesium deficiency＋100 $\mu$M aluminium>100$\mu$M aluminium>magnesium deficiency>control. In addition to Mg deficiency and Al toxicity, growth decline of pitch pine widely occurring in polluated Seoul could to a large extent be due to cuticle degredation and abnormal vertical distribution of fine roots, which lead to water stress, particularly in dry seasons.

• The Korean Journal of Mycology
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• v.14 no.1
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• pp.17-23
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• 1986

The mating system of monokaryotic isolates in Pleurotus sajor-caju was controlled by two incompatibility factors A and B of tetrapola mating system. The mycelia of dikaryotic isolates grew faster than those of their component monokaryons, but no correlation between dikaryotic and their component monokaryotic isolates was found. The primodia formed well on the potato dextrose agar (PDA) media not only in the dikaryotic isolates but also in the monokaryons under irradiated conditions. The dikaryotic isolates produced normal sporophores; however, the monokaryotic isolates produced abnormal sporophores when they were cultivated with sawdust substrates. Some dikaryotic isolates derived by mating between monokaryotic isolates showed high yields of sporophores more than those of parental strains. Both the dikaryotic mycelial growth rate and primodia formation number on the PDA plate showed significant correlation with its sporophore products on sawdust substrates.

• 한국균학회소식:학술대회논문집
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• 2018.05a
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• pp.11-11
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• 2018

Cryphonectria parasitica, chestnut blight fungus, has a characteristic of decreasing pathogenicity when infected with Cryphonectria hypovirus 1. C. parasitica is known to be one of the most representative model systems used to observe the interaction between viruses, plants and fungi. The mitogen-activated protein kinase (MAPK) pathway, which is well conserved in various organisms ranging from yeast to humans, functions in relaying phosphorylation-dependent signals within MAPK cascades to diverse cellular functions involved in the regulation of pheromone, cell wall integrity, and osmotolerance in filamentous fungi. Several genes in the MAPK pathway were revealed to be regulated by hypovirus, or to be involved in pathogenicity in C. parasitica. Among these pathways, the CWI pathway has aroused interest because CpBck1, an ortholog of yeast Bck1 (a CWI MAPKKK), was previously reported to be involved in cell wall integrity and sectorization. Interestingly, sporadic sectorization was observed in the CpBck1 mutant and sectored phenotypes were stably inherited in the progeny that were successively transferred from sectored mycelia. In this study, we analyzed the biological function of CpSlt2, downstream gene of CpBck1, to confirm whether the sectorization phenomenon occurred in the specific single gene or cell wall integrity (CWI) pathway. As results, the CpSlt2-null mutant exhibited marked changes in colonial growth, near absence of conidiation and aerial hyphae, abnormal pigmentation, CWI-related phenotypic defects, and dramatically impaired virulence. As cultivation of the mutant strains progressed, the majority of the colonies showed sporadic sectorization and mycelia from the sectored area stably maintained the sectored phenotype. These results suggest that the unique sectorization is CWI pathway-specific, though the components in the same CWI pathway have common and specific functions.

• Korean Journal of Veterinary Research
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• v.40 no.2
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• pp.311-323
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• 2000

Immunosuppressive effects of reticuloendotheliosis virus (REV) infection in chickens were investigated. Primary antibody responses to Newcastle disease virus (strain B1) and sheep red blood cells were significantly low in chickens inoculated with the local isolate 89-74 of REV compared to those of uninfected chickens. In chickens infected with REV strain T or 89-74, blastogenesis of spleen cells and peripheral blood lymphocytes (PBL) to concanavalin A (Con A) was severely suppressed. When specific pathogen free (SPF) chickens were inoculated with the isolate, the suppressive effect was observed up to 7 weeks of age while, in the contact infected chickens, the suppression was absent. Similar suppressive effects were observed in chickens inoculated with REV strain T at 2, 3 and 4 weeks of age. When spleen cells or PBL from uninfected chickens were co-cultured with spleen cells or PBL from chickens infected with REV at 1 day-old or 2 week-old, the blastogenesis of the normal cells was suppressed. The suppressive effect of PBL from REV-infected chickens on normal lymphocytes was abrogated by the treatment with trypsin. However the suppressive activity of the REV-infected PBL was not influenced at removing machrophage from the cell suspension by incubation in plastic petri dishes. In addition to the immunosuppression, chickens infected with the REV isolate showed abnormal feather development (nakanuke), anemia, paralysis and retarded growth. Three out of 11 chickens inoculated with the isolate at day-old died between 6 and 9 weeks of age by bacterial infections.