• Horticultural Science & Technology
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• v.33 no.1
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• pp.114-123
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• 2015

Plants can respond and adapt to cold stress through regulation of gene expression in various biochemical and physiological processes. Cold stress triggers decreased rates of metabolism, modification of cell walls, and loss of membrane function. Hence, this study was conducted to construct coexpression networks for time-based expression pattern analysis of genes related to cold stress in Chinese cabbage (Brassica rapa ssp. pekinensis). B. rapa cold stress networks were constructed with 2,030 nodes, 20,235 edges, and 34 connected components. The analysis suggests that similar genes responding to cold stress may also regulate development of Chinese cabbage. Using this network model, it is surmised that cold tolerance is strongly related to activation of chitinase antifreeze proteins by WRKY transcription factors and salicylic acid signaling, and to regulation of stomatal movement and starch metabolic processes for systemic acquired resistance in Chinese cabbage. Moreover, within 48 h, cold stress triggered transition from vegetative to reproductive phase and meristematic phase transition. In this study, we demonstrated that this network model could be used to precisely predict the functions of cold resistance genes in Chinese cabbage.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.377-384
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• 2018

This study focused on the effects of feeding on postlarvae of shrimp, Litopenaeus vannamei, during the identified acclimation time to low salinity. A total of 5 different salinity groups with or without feeding (32, 24, 16, 8, and 2 psu, 1 liter, triplicates) were prepared, and 30 shrimp were settled at PL21 (postlarvae) and placed in each group. After 24 hours of the experimentation process, the survival rate of the fed and starved groups was observed to be lower in the 2 psu group compared to other salinity groups, with the rate of 86.6% and 81.1%, respectively. The condition index of glucose and triglyceride, which are important factors for osmoregulation and as energy sources, was 4.2-7.6 times and 2.7-3.4 times higher in the fed groups than the starved groups at all the levels of salinities. The creatine level increased by 1.1-1.5 times in the starved groups as compared to the fed groups. Likewise, the activity of all the digestive enzymes like, lipase, ${\alpha}$-amylase, trypsin, and alkaline protease were clearly higher in the fed groups (ANOVA, p<0.05). Apparently, it was observed that feeding is effective for the postlarvae of shrimp, which shows a characteristic fast metabolism and larval development, during the acclimation period to low salinity.

• KOREAN POULTRY JOURNAL
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• v.41 no.6
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• pp.98-102
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• 2009

닭의 피부는 땀샘(汗腺)이 없어서 증산작용으로 체온발산이 불가능하기 때문에 고온의 환경하에서는 입을 벌려 헐떡거림(panting)을 위주로 체온을 발산시키고, 일부는 볏, 고기수염, 얼굴 등을 통하여 증발작용을 한다. 특히 육계는 증체가 빠르고 이를 뒷받침하기 위한 체내 대사가 활발하기 때문에 여름철을 슬기롭게 대처하기 위한 세심한 주의가 요구된다. 우리나라와 같이 여름철 고온다습(高溫多濕)한 기후조건에서 계사 환경온도 유지가 어렵고, 열 스트레스를 줄이는 것이 쉽지 않다. 농장주는 여름철 더위에 의한 생산성 저하는 물론이고, 짧은 시간에 닥칠 수도 있는 혹서기 대량폐사를 막기 위하여 외부환경 변화상황을 주지하고서 각자가 소유하고 있는 계사의 환경과 닭의 상태를 주의 깊게 관찰함은 물론 피해를 최소한으로 감소시키기 위한 나름대로의 노하우를 가지고 대처하지 않으면 애써 노력한 결과가 혹서기 잠깐 사이에 큰 피해를 초래할 수도 있다는 인식을 가지고 있어야 한다. 환경온도와 상대습도 등의 생활에 큰 영향을 미친다. 환경온도, 상대습도 등이 닭의 생리에 미치는 영향을 알아보고 혹서기와 우기에 닭 사양관리를 알아보자.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.17-22
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• 2005

Sleep-disordered breathing (SDB) is associated with increased cardiovascular and cerebrovascular morbidity. Epidemiological and clinic-based studies have shown that SDB is related to impaired glucose tolerance and increased insulin resistance, independent of obesity. Despite of a consistent association between SDB and impaired glucose-insulin metabolism, the mechanism underlying this relationship has not been fully elucidated. It is recognized that hypoxemia and hypercapnia that occur in SDB provoke sympathetic nervous activity and catecholamine, epinephrine and norepinephrine, and cortisol are released. Sympathetic hyperactivity and increased catecholamines can impair glucose homeostasis by increasing glycogenolysis and gluconeogenesis, which can result in increased circulating insulin levels and increased risk of insulin resistance. A prospective study is needed to investigate the causal relationship between SDB and impaired glucose-insulin metabolism in a healthy population without diabetes, hypertension and obesity as etiologic risk factors.

• Applied Microscopy
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• v.39 no.4
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• pp.333-340
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• 2009

In the present study, ultrastructural features of the mesophyll tissue have been investigated in Crassulacean acid metabolism (CAM)-performing succulent Orostachys. A large central vacuole and numerous small vacuoles in the peripheral cytoplasm were characterized at the subcellular level in both developing and mature mesophyll cells. The most notable feature was the invagination of vacuolar membranes into the secondary vacuoles or multivesicular bodies. In many cases, tens of single, membrane-bound secondary vacuoles of various sizes were found to be formed within the central vacuole. multivesicular bodies containing numerous small vesicles were also distributed in the cytoplasm but were better developed within the central vacuole. Occasionally, electron-dense prevacuolar compartments, directly attached to structures appearing to be small vacuoles, were also detected in the cytoplasm. One or more huge central vacuoles were frequently observed in cells undergoing differentiation and maturation. Consistent with the known occurrence of morphologically distinct vacuoles within different tissues, two types of vacuoles, one representing lytic vacuoles and the other, most likely protein storage vacuoles, were noted frequently within Orostachys mesophyll. The two types coexisted in mature vegetative cells but did not merge during the study. Nevertheless, the coexistence of two distinct vacuole types in maturing cells implies the presence of more than one mechanism for vacuolar solute sorting in these species. The vacuolar membrane is known to be unique among the intracellular compartments for having different channels and/or pumps to maintain its function. In CAM plants, the vacuole is a very important organelle that regulates malic acid diurnal fluctuation to a large extent. The membrane invagination seen in Orostachys mesophyll likely plays a significant role in survival under the physiological drought conditions in which these Orostachys occur; by increasing to such a large vacuolar volume, the mesophyll cells are able to retain enormous amounts of acid when needed. Furthermore, the mesophyll cells are able to attain their large sizes with less energy expenditure in order to regulate the large degree of diurnal fluctuation of organic acid that occurs within the vacuoles of Orostachys.

• Korean Journal of Weed Science
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• v.17 no.2
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• pp.199-206
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• 1997

Chlorsulfuron, an acetolactate-synthase-inhibiting sulfonylurea herbicide, induces many metabolic and physiological changes in susceptible plants. The objective of this study was to determine to what extent chlorsulfuton-induced phytotoxicity was due to a shortage of final products(the branched-chain amino acids valine, leucine, and isoleucine) or to an accumulation of a toxic metabolite(2-ketobutyrate), or both, in a susceptible species. Chlorsulfuron-treated canola seedlings showed growth inhibition and injury symptoms that included chlorosis, downward leaf rolling, and accumulation of anthocyanins. Supplementation with valine, leucine, and isoleucine prevented the chlorsulfuron-induced growth inhibition and injury symptoms only partially, suggesting that factor(s) other than a shortage of the branched-chain amino acids also are involved in the phytotoxicity. Canola seedlings treated with 2-ketobutyrate showed reduced growth, but they showed different changes in metabolites than seedlings treated with chlorsulfuron. The results suggest that 2-ketobutyrate is not involved in chlorsulfuron-induced phytotoxicity. We conclude that chlorsulfuron-induced phytotoxicity is due at least in part to a shortage of branched-chain amino acids.

• Journal of Nutrition and Health
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• v.31 no.9
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• pp.1377-1384
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• 1998

The purpose of this study was to investigate the effect of H$_2$O fraction of Dioscorea japonica Thunb(DJT) with selenium(Se) treatment on blood glucose and lipid metabolism in streptozotocin(STZ)-induced diabetic rats. Male Sprague-Dawley rats(180-220g) weighing were divided into five groups, that is one normal group and four diabetic experimental groups : the STZ-control group, the DJT group, the DJT-Se group and the Se group. Diabetes mellitus was induced in the male rats by injection of STZ into the tail vein at a dose of 45mg/kg B.W. The H,0 fraction of DJT(500mg/kg) given orally were administered for 14 days. The Se treated group were fed a AIN-76 recommendation diet mixed with Na$_2$SeO$_3$(2mg/kg diet), which was prepared fresh daily. The body weight and food intake was monitored daily and plasma levels of glucose, insulin, hematocrit and protein were determined. The plasma concentrations of cholesterol, HDL-cholesterol, triglyceride and fire fatty acid were measured. The activities of aminotrans ferase were analysed. The body weight gain was shown to be significantly higher in the normal group than all diabetic groups. The blood glucose levels of the DIT-Se group was significantly lower compared to those of the experimental groups. The administration of H$_2$O fraction of DJT and selenium showed an increase in plasma protein concentrations. The plasma cholesterol levels of all STZ-groups were not significantly different and HDL-cholesterol levels were increased in the diabetic experimental groups fed on H$_2$O fraction of DJT or Se supplementation. Plasma triglyceride levels were lower in the DJT-Se and Se group than in the STZ-control group. free fatty acid levels were not significantly differ among STZ-control groups. STZ treatment increased aminotransferase activity and that of DJT group was highest. In conclusion, the data from the present experiments indicate that the treatment of the H$_2$O fraction of DJT with selenium showed a synergistic effect and the two can have an influence on hyperg1ycemia and lipid metabolites when administered together. (Korean J Nutrition 31(9) : 1377-1384, 1998)

• Journal of Life Science
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• v.27 no.7
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• pp.826-833
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• 2017

The rising concentration of atmospheric carbon dioxide is causing ocean acidification and global warming. The seahorse is an important species in marine ecosystems and fishery markets, however, their populations have recently decreased due to ocean acidification. As a result, we examined changes in the physiological responses of the spotted seahorse Hippocampus kuda when it was exposed to acidic sea water (pH 6.0, 6.5, and 7.0) and normal seawater (pH 8.0 as the control) over a period of 15 days. As the pH decreased, the seahorses' body weight and length also decreased. Components in body of ash, the crude lipids and crude proteins also differed significantly with changes in pH, due to stress caused by the seahorses' exposure to the acidic water conditions. The superoxide dismutase levels were significantly lower in the pH 6.0 and 6.5 groups than they were in the pH 7.0 and pH 8.0 groups. However, the catalase and glutathione levels were significantly higher in the acidic sea water groups. We suggest that decreasing the pH level of rearing water induces a stress response in H. kuda, damaging their ability to maintain their homeostasis and energy metabolism. Antioxidant enzymes are generally sensitive to acidic stress; in this study, the antioxidant activity was significantly affected by the pH level of the rearing water. These results indicate that physiological stress, induced by exposure to acidification, induces an antioxidant reaction, which can reduce general components in the body and the growth of H. kuda.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.105-111
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• 2005

Streptomyces produces many kinds of secondary-metabolites including antibiotics. Screening of a new compound and elucidation of a biosynthetic pathway for the secondary metabolites are very important fields of biology, however, there is a main problem that most of the identified compounds are already researched compounds. To solve these problems, a microarray system that is based on the data related to the biosynthetic genes for secondary-metabolites was designed. For the main contents of DNA microarray, the important genes for the bio-synthesis of aminoglycosides, polyenes group, enediyne group, alpha-glucosidase inhibitors, glycopeptide group, and orthosomycin group were chosen. A DNA microarray with 69 genes that were involved in the bio-synthesis for the antibiotics mentioned above was prepared. The usability of the DNA microarray was confirmed with the chromosomal DNA and total RNA extracted from S. coelicolor whose genomic sequence had already been reported.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.91-96
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• 2000

The cultural and physiological conditions for the T-2 toxin [4,15-diacetoxy-8-(3-mety1butyloxy)-12,13- epoxy-trichothec-9-en-3-01, $C_{24}H_{30}O_9$] production by Fusarium spp. were studied. Thin layer chromatography (TLC) assay and the microbiological assay uslng Rhodotomla rubra were used to quantitate tbe T- 2 toxin. Among the four strains of Fusarium spp., F tn'cinctum NRRL 3299 was best for T-2 toxin production. In solid culture, white com grit medium was best for T-2 toxm production. Temperature played a critical role in the production of T-2 toxin. T-2 toxin production was favored by long duration of low-temperature incubation. The growth and toxin production were relatively high on galactose, fructose, glucose, and sucrose media, when each was used as a sole carbon source, and relatively low on sorbitol, glycerol, and lactose media. For nitrogen sources, $NH_4^(+) and NO_3^{-}were used well as a sole nitrogen source, but $NO_2^-$ was not used. Initial pH and speed of shaker also affected the production of T-2 toxin. From temperature shifting experiment, it is clear that T-2 toxin metabolic pathway is regulated by temperature-dependent enzyme depression or enzyme induction system.