• Development and Reproduction
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• v.18 no.3
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• pp.161-166
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• 2014

Previously, we demonstrated that the shift and/or restriction of feeding time during relatively short-term period (4 weeks) could alter the pituitary gonadotropin expression and the weights of seminal vesicle and prostate in rats. We also found that the reverse feeding (RF) schedule (up to 8 weeks) might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues. In the present study, we extended the RF time regimen up to 12 weeks, and measured the reproductive tissue weights. After 4 and 8 weeks of RF, the weights of epididymis were not significantly different. After 12 weeks, however, epididymis weights of RF animals were significantly different (CON 12W : RF 12W = $48.26{\pm}0.62mg$ : $44.05{\pm}1.57mg$, p<0.05). After 4 and 12 weeks of feeding, seminal vesicle weights of RF animals were significantly decreased (CON 4W : RF 4W = $79.36{\pm}8.34mg$ : $46.28{\pm}2.43mg$, p<0.001; CON 12W : RF 12W = $72.04{\pm}3.76mg$ : $46.71{\pm}2.27mg$, p<0.001, respectively). Prostate weights were not changed by RF. Kidney and spleen weights of RF animals were significantly different on weeks 4 and 12 (Kidney, CON 4W : RF 4W = $249.72{\pm}4.20mg$ : $228.41{\pm}3.03mg$, p<0.001; CON 12W : RF 12W = $309.15{\pm}7.49mg$ : $250.72{\pm}6.13mg$, p<0.001, respectively, Spleen, CON 4W : RF 4W = $111.26{\pm}3.76mg$ : $96.88{\pm}4.69mg$, p<0.05; CON 12W : RF 12W = $123.93{\pm}10.72mg$ : $94.68{\pm}5.65mg$, p<0.05, respectively). Histology analysis of seminal vesicle revealed that the thinner epithelial cell layers, reduced complexities of swollen papilla folding in the exocrine glands on weeks 4 and 12 of RF. There was no histological difference between control and RF group on week 8. The present study indicates that up to 12 weeks RF induced differential changes in tissue weights of male mice. In particular, seminal vesicle, kidney and spleen seemed to temporarily adapted to the RF-induced metabolic stress on week 8 of feeding schedule. These results confirmed the our previous study that the RF might induce an adaptable metabolic stress and cause impairment of androgen-dependent reproductive tissues such as epididymis and seminal vesicle as well as non-reproductive tissues such as kidney and spleen. Further studies will be needed to achieve a better understanding of the how does mealtime shift affect the reproductive function and exact nature of adaptation.

• Microbiology and Biotechnology Letters
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• v.32 no.4
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• pp.341-346
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• 2004

The quantification of the toxicological effects of the heavy metals such as Cu, Cd, Cr, Hg, and Zn on the growth of Escherichia coli was performed, and the variations of toxicwith exposure time were evaluated in adaptation procedure. The characteristics of growth inhibition on Escherichia coli by heavy metals were different with metal species, and critical concentration of each metal, which inhibited cell growth completely, were Cu of 3.5 mM, Zn of 2.5 mM, Cd of 1.5 mM, Cr of 1.2 mM, and Hg of 0.12 mM, respectively. The tolerance of E. coli against heavy metals, based on $EC_{50}$ values, increased in order of Cu > Zn > Cr > Cd > Hg. The slopes obtained from the relationship between ECso values and expose time corresponds to adaptability of test organisms to the toxicants. The adaptability of test organisms to the toxicants was much higher at higher slope values. Adaptability of E. coli on heavy metals increased in order to Zn > Cd > CU >> Cr> Hg.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.534-538
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• 2013

The effects of lights with different wavelengths on the growth and the yield of extracellular polysaccharides of Nostoc flagelliforme cells were investigated in a liquid cultivation. N. flagelliforme cells were cultured for 16 days in 500 ml conical flasks containing BG11 culture medium under $27{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light intensity and $25^{\circ}C$ on a rotary shaker (140 rpm). The chlorophyll a, phycocyanin, allophycocyanin, and phycoerythrin contents in N. flagelliforme cells under the lights of different wavelengths were also measured. It was found that the cell biomass and the yield of polysaccharide changed with different wavelengths of light. The biomass and the yield of extracellular polysaccharides under the red or violet light were higher than those under other light colors. Chlorophyll a, phycocyanin, and allophycocyanin are the main pigments in N. flagelliforme cells. The results showed that N. flagelliforme, like other cyanobacteria, has the ability of adjusting the contents and relative ratio of its pigments with the light quality. As a conclusion, N. flagelliforme cells favor red and violet lights and perform the complementary chromatic adaptation ability to acclimate to the changes of the light quality in the environment.

• Journal of Radiation Protection and Research
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• v.28 no.2
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• pp.117-125
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• 2003

It was reported that radiopharamaceuticals induced radiation adaptive response (RAR) in patients undergoing nuclear medicine imaging studies. Individual variations of RAR were not studied well. The purpose of this study was to evaluate individual variation of RAR in patients undergoing nuclear medicine imaging studies. Peripheral lymphocytes were collected from 23 patients undergoing $^{99m}Tc-diethylenetriamine$ pentaacetic acid $(^{99m}Tc-DTPA)$ renal scintigraphy, 18 patients undergoing $^{99m}Tc-methylene$ diphosphonate $(^{99m}Tc-MDP)$ bone scintigraphy and 21 patients undergoing $^{99m}Tc-tetrofosmin\;(^{99m}Tc-TF)$ scintigraphy were collected before and 4 hours after injection of radiopharmaceuticals. The lymphocytes were exposed to challenge dose of 2 Gy gamma rays using a cell irradiator. Numbers of ring-form (R) and dicentric (D) chromosomes were counted under the light microscope. and used to calculate the frequency of chromosomal aberration [Ydr=(D+R)/total number of counted lymphocytes]. Adaptation index (k) was defined 3s ratio of Ydr in conditioned lymphocytes over Ydr in unconditioned lymphocytes. Coefficients of variance of k in $^{99m}Tc-DTPA,\;^{99m}Tc-MDP\;and\;^{99m}Tc-TF$ were 35%, 34% and 21%, respectively k was not dependent upon age, sex, and underlying diseases. There was a wide variation of RAR induced by radiopharmaceuticals among patients undergoing nuclear medicine procedures. It remains to be determined for causes of such variation.

• Journal of Life Science
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• v.26 no.8
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• pp.976-982
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• 2016

Seaweed has high growth rate, low land usage, high CO₂ absorption and no competition for food resources. Therefore, the use of lignin-free seaweed as a raw material is arising as a third generation biomass for bioethanol production. Various pretreatment techniques have been introduced to enhance the overall hydrolysis yield, and can be categorized into physical, chemical, biological, enzymatic or a combination. Thermal acid hydrolysis pretreatment is one of the most popular methods to attain high sugar yields from seaweed biomass for economic reasons. At thermal acid hydrolysis conditions, the 3,6-anhydro-galactose (AHG) from biomass could be converted to 5-hydroxymethylfurfural (HMF), which might inhibit the cell growth and decrease ethanol production. AHG is prone to decomposition into HMF, due to its acid-labile character, and subsequently into weak acids such as levulinic acid and formic acid. These inhibitors can retard yeast growth and reduce ethanol productivity during fermentation. Thus, the carbohydrates in seaweed require effective treatment methods to obtain a high concentration of monosaccharides and a low concentration of inhibitor HMF for ethanol fermentation. The efficiency of bioethanol production from the seaweed biomass hydrolysate is assessed by separate hydrolysis and fermentation (SHF). To improve the efficiency of the ethanol fermentation of mixed monosaccharides, the adaptation of yeast to high concentration of sugar could make simultaneous utilization of mixed monosaccharides for the production of ethanol from seaweed.

• Journal of Life Science
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• v.27 no.12
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• pp.1415-1420
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• 2017

The metallothionein (MT) gene (IbMT3) was selected from an EST library of suspension-cultured sweet potato cells. The MT gene, which is one of abundant ESTs in the library, is involved in stress regulation of cells and tissues. A full-length IbMT3 cDNA was obtained and analysis of its nucleotide sequence revealed that IbMT3 encoded a type 3 MT protein, based on its structural characteristics. The function of type 3 MT in plants is not yet known. Northern blot analysis showed stronger expression of IbMT3 in suspension-cultured cells than in sweet potato plant leaves. Since cell culture is known to impose a state of oxidative stress on cells, sweet potato plants were subjected to oxidative stress to investigate the transcriptional regulation of IbMT3. When the herbicide methyl viologen (MV) was administered for 6, 12, and 24 hr, IbMT3 transcription rapidly increased at 6 hr and then decreased. A cold treatment at $15^{\circ}C$ for 24 and 48 hr resulted in a gradual increase in IbMT3 expression. These findings indicate that IbMT3 expression is regulated in response to environmental and oxidative stress. IbMT3 isoform is expected to have antioxidant effects in sweet potato plants and may play an important role in cellular adaptation to oxidative stress.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.298-306
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• 2016

Planting date shift is one of the means of adapting to climate change in Kimchi Cabbage growers in major production areas in Korea. This study suggests a method to estimate the potential yield of Kimchi Cabbage based on daily temperature accumulation during the growth period from planting to maturity which is determined by a plant phenology model tuned to Kimchi Cabbage. The phenology model converts any changes in the thermal condition caused by the planting date shift into the heat unit accumulation during the growth period, which can be calculated from daily temperatures. The physiological maturity is estimated by applying this model to a variable development rate function depending either on growth or heading stage. The cabbage yield prediction model (Ahn et al., 2014) calculates the potential yield of summer cabbage by accumulating daily heat units for the growth period. We combined these two models and applied to the 1km resolution climate scenario (2000-2100) based on RCP8.5 for South Korea. Potential yields in the current normal year (2001-2010) and the future normal year (2011-2040, 2041-2070, and 2071-2100) were estimated for each grid cell with the planting dates of July 1, August 1, September 1, and October 1. Based on the results, we divided the whole South Korea into 810 watersheds, and devised a three - dimensional evaluation chart of the time - space - yield that enables the user to easily find the optimal planting date for a given watershed. This method is expected to be useful not only for exploring future new cultivation sites but also for developing cropping systems capable of adaptation to climate change without changing varieties in existing production areas.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.3
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• pp.94-101
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• 2008

Warming trends during winter seasons in East Asian regions are expected to accelerate in the future according to the climate projection by the Inter-governmental Panel on Climate Change (IPCC). Warmer winters may affect short-term cold hardiness of deciduous fruit trees, and yet phenological observations are scant compared to long-term climate records in the regions. Dormancy depth, which can be estimated by daily temperature, is expected to serve as a reasonable proxy for physiological tolerance of flowering buds to low temperature in winter. In order to delineate the geographical pattern of short-term cold hardiness in grapevines, a selected dormancy depth model was parameterized for "Campbell Early", the major cultivar in South Korea. Gridded data sets of daily maximum and minimum temperature with a 270m cell spacing ("High Definition Digital Temperature Map", HDDTM) were prepared for the current climatological normal year (1971-2000) based on observations at the 56 Korea Meteorological Administration (KMA) stations and a geospatial interpolation scheme for correcting land surface effects (e.g., land use, topography, and site elevation). To generate relevant datasets for climatological normal years in the future, we combined a 25km-resolution, 2011-2100 temperature projection dataset covering South Korea (under the auspices of the IPCC-SRES A2 scenario) with the 1971-2000 HD-DTM. The dormancy depth model was run with the gridded datasets to estimate geographical pattern of change in the cold-hardiness period (the number of days between endo- and forced dormancy release) across South Korea for the normal years (1971-2000, 2011-2040, 2041-2070, and 2071-2100). Results showed that the cold-hardiness zone with 60 days or longer cold-tolerant period would diminish from 58% of the total land area of South Korea in 1971-2000 to 40% in 2011-2040, 14% in 2041-2070, and less than 3% in 2071-2100. This method can be applied to other deciduous fruit trees for delineating geographical shift of cold-hardiness zone under the projected climate change in the future, thereby providing valuable information for adaptation strategy in fruit industry.

• Journal of Life Science
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• v.26 no.7
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• pp.812-818
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• 2016

The aim of this study was to investigate the anti-amnesic effect of Stachys sieboldii MIQ. according to the mixing ratio of calcium on scopolamine-induced learning and memory impairment, in vivo. At the end of the adaptation period, SD rats were divided into a normal group (N), a control group (C: scopolamine), a positive control group (PC: scopolamine + tacrine), and a sample group (S: scopolamine + Stachys sieboldii MIQ., 1CS: scopolamine + low calcium-mixed Stachys sieboldii MIQ., 5CS: scopolamine + high calcium-mixed Stachys sieboldii MIQ.), and were tested with learning and memory tests. The C and CS groups were found to have a decreased scopolamine-induced memory deficit in the Y-maze and water maze tests. Brain tissue analysis showed that the CS group decreased acetylcholinesterase (AChE) activity and increased acetylcholine (Ach) content, both of which are indicative of neuronal cell activity. From a light microscopy study, the nucleus of neurons in the hippocampus of the brain was more shrunken or condensed in the C group compared to the CS group. In the CS group, the damage to the neurons in the hippocampus of the brain was suppressed. These results suggest that Stachys sieboldii MIQ. according to the mixing ratio of calcium provides a significant anti-amnesic effect against scopolamine-induced cholinergic system deficits and cognitive impairment.

• Journal of Life Science
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• v.23 no.2
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• pp.324-331
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• 2013

The addition and removal of N-acetylglucosamine (GlcNAc) molecules on serine or threonine residues of a protein is called O-GlcNAcylation. This post-translational modification occurs on both cytoplasmic and nuclear protein, and is fast and reversible as comparable to phosphorylation. In contrast to the phospho-signaling cycles, this emerging moon-lightening signaling is cycled by only two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). The simple machinery is a good evolutionary adaptation of a cell for quick accommodation to continuously fluctuating intra- and extracellular microenvironments. Rather than "switching" on or off a specific proteins - this would be done by phosphorylation where numerous specific kinases and phosphatases are involved - O-GlcNAcylation would play a "rheostat" which would be much more delicately increase or decrease the efficacy of signal transductions in response to cellular nutrient and stress conditions. Interestingly, recent evidence indicates that O-GlcNAc is further modified by phosphorylation. The O-GlcNAc-P will upgrade the modulation efficiency of cellular processes to continuous 'analogue' level. So far, only one protein AP180 was reported to have O-GlcNAc-P on Thr310. But, proteomic data from our laboratory indicate that there are multiple O-GlcNAc-P proteins, constituting "O-GlcNAc-P'om". This will focus on the possibility of existence of "O-GlcNAc-P'om".