• Journal of Conservation Science
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• v.34 no.6
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• pp.459-470
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• 2018

Cellulose nitrates were used for folklore artifacts(ornamental beads and pipes in hatstrings, frames of eyeglasses, ornamental eyeglass cases, headband ornaments, and jeogori buttons) between the 19th and 20th centuries; however, they are susceptible to cracking, crazing, embrittlement, and crumbling due to deterioration. To consolidate and adhere deteriorated cellulose nitrate folklore artifacts, water-soluble acrylic emulsion adhesives were investigated. For consolidation, Plextol D 498, which has the lowest viscosity in low concentrations, was used. In adhesive films whose glass transition temperature(Tg) is lower than room temperature, the tensile stress and modulus decreased and the strain increased; therefore, the flexibility was high. The Plextol D 498 and Plextol D 498 and Dispersion K 52 films maintained their adhesiveness and flexibility after artificial-sunlight-accelerated ageing, and Plextol D 498 and Dispersion K 52 films hardly caused yellowing. Plextol D 498 was the most stable for accelerating ageing. A low concentration of Plextol D 498 emulsion resulted in the best permeability on the surface of cellulose nitrate, compared with other acrylic emulsions. To prevent ornamental hatstrings from cracking, crazing, embrittlement, and crumbling, a Plextol D 498 emulsion was used. After applying low concentrations(1%, 3%) of the emulsion to consolidate the fragments and high concentration to adhere the fragments, the ornamental hatstrings were protected from crumbling by deterioration, and their fragments were well-adhered. To preserve it from deterioration by oxygen and humidity, the treated ornament was sealed with an oxygen-barrier film using a low-humidity oxygen scavenger.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.354-364
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• 2020

This study was conducted to examine the potential of inducing salinity stress on cylindrical paper pot tomato seedlings to inhibit overgrowth. Potassium fertilizers, sulfate of potash (K₂SO₄), muriate of potash (KCl), and monopotassium phosphate (KH₂PO₄), were prepared as two solutions of (5 and 10) dS·m^-1 salinity level, respectively, to investigate the influence on tomato (Lycopersicon esculentum Mill.) seedling growth. We also investigated the adaptability and survivability of treated tomato seedlings with high-salinity potassium (10 dS·m^-1 KCl) to harsh environmental conditions (water deficit, low temperature, and storage conditions). Repeated addition of high-salinity level KCl, K₂SO₄, or KH₂PO₄ markedly decreased the dry matter of shoot and root, leaf area, and net assimilate rates (NAR) but increased the stem diameter of seedlings. Among the three sources, the relative growth rate of plant height (RGR_H) was most sensitive to KCl addition; increasing salinity levels of KCl solution decreased the RGR_H of seedlings. The compactness, which directly reflects the stocky growth index, increased in KCl or KH₂PO₄ treatments. After a week's water deficit, severely wilted seedlings were observed in control seedlings (untreated with KCl), but no wilted seedlings were observed in the KCl treated seedlings, and the relative water content (RWC) of the untreated seedlings significantly decreased by 23 %, while that of the pretreated seedlings only decreased by 8 %. The increase in ion leakage of KCl treated seedlings at low temperatures was less than that of untreated seedlings. Furthermore, there was far lower damage proportion on pretreated seedlings at (9, 12, and 15)℃ storage temperatures after 20 days, compared with on unpretreated seedlings. Our results suggest that high-salinity potassium fertilizer, especially KCl, is effective in preventing tomato seedling overgrowth, while it also improves tolerance.

• Journal of Life Science
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• v.28 no.6
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• pp.639-647
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• 2018

A new heat shock protein 70 was identified in red-spotted grouper (Epinephelus akaara) based on an expression analysis. The cDNA of red-spotted grouper Hsp70 (designated RgHsp70) was cloned by the rapid amplification of cDNA ends (RACE) techniques. The full-length of RgHsp70 cDNA was 2,152 bp, consisting of a 5'-terminal untranslated region (UTR) of 105 bp, a 3'-terminal UTR of 274 bp, and an open reading frame (ORF) of 1,773 bp that encode a polypeptide of 590 amino acids with a theoretical molecular weight of 64.9 kDa and an estimated isoelectric point of 5.2. Multiple alignment and phylogenetic analyses revealed that the RgHsp70 gene shares a high similarity with other Hsp70 fish genes. RgHsp70 contained all three classical Hsp70 family signatures. The results indicated the RgHsp70 is a member of the heat shock protein 70 family. RgHsp70 mRNA was predominately expressed in the liver, with reduced expression noted in the head-kidney tissues. The expression analysis of different water temperatures (21, 18, 15 and $12^{\circ}C$) for sampled livers revealed that expression gradually increased at $12^{\circ}C$ compared to $21^{\circ}C$. In this study, the effects of water temperature lowering on the physiological conditions were investigated, and the results revealed that novel RgHsp70 may be an important molecule involved in stress responses.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.299-307
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• 1988

Several experiments were conducted to investigate the effects of external factors on germination and emergence of Eclipta prostrata (L.)L. The weight of viable achenes doubled as a result of 90 minutes soaking in water. The germination of E. prostrata was significantly improved by alternating temperatures. At a constant temperature of $35^{\circ}C$, only 78% of the achenes germination, whereas at alternating temperatures of 35/$20^{\circ}C$, 96.5% of the achenes germinated. E. prostrata was more sensitive than rice to moisture stress. No germination of E. prostrata achenes occurred in the absence of oxygen. No germination of E. prostrata achenes occurred in the dark or when they were exposed to green, blue, and far-red light. Germination of E. prostrata achenes was influenced by the duration of illumination after absorption of water. Ten hours of illumination was needed for maximum germination and 2 hours for 50% germination. No significant changes in germination of E. prostrata achenes were observed between pH 3 and 10. A high tolerance of E. prostrata achenes to salt was observed. Emergence of E. prostrata achenes was greatly affected by planting depth. In the upland soil, 74.0% of the achenes planted on the soil surface germinated, and no emergence was at planting depths of 0.5 cm or greater.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.131-138
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• 2003

A toxicological study of the pesticides for rice paddy to loach was conducted with iprobenfos 17% GR, diazinon 3 % GR, and butachlor 5 % GR to establish the field test method and their toxicological effects on loach under the actual field conditions. The type C of cage was more effective in the sense of a little stress from the cage. The nets for shading and for preventing the birds were necessary to maintain the water temperature and to prevent the predators. The cumulative mortality of loach exposed to iprobenfos 17% GR, diazinon 3% GR and butachlor 5% GR were 10, 55 and 22%, respectively, during 7 days of exposure. The averaged concentration of the pesticides in paddy water 2 days after application were 1.67, 0.22 and 0.26 mg/L, and mortalities were 7, 50 and 17%, respectively, representing the similar results with acute toxicity $(48h-LC_{50})$.

• Journal of Life Science
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• v.27 no.10
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• pp.1111-1120
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• 2017

This study was conducted to select pepper lines that were tolerant to excessive water injury among the pepper germplasm and investigate the genetic characteristics of those lines to contribute to the breeding of pepper cultivars with stable productivity in abnormal weather. Each of the tolerant and susceptible lines went through immersion treatment, and differentially expressed genes between them were analyzed. The tolerant line showed increased expression of the CA02g26670 gene, which is involved in the CONSTANS protein pathway and regulation of flowering by day length, but it exhibited decreased expressions of CA01g21450, CA01g22480, CA01g34470, CA02g00370 and CA02g00380. The susceptible line showed increased gene expressions of CA02g09720, CA02g21290, CA03g16520, CA07g 02110, and CA12g17910, which are involved in the inhibition of proteolytic enzyme activity, DNA binding, inhibition of cell wall-degrading enzyme, and inhibition of nodulin, respectively. Meanwhile the expressions of CA02g02820, CA03g21390, CA06g17700 and CA07g18230 decreased in the susceptible line, in relation to calcium-ion binding, high temperature, synthesis of phosphocholine and cold stress, respectively. The expressions of genes related to apoptosis and peroxidase increased, while that of CA02g16990, which functions as a nucleoside transporter, decreased in both the tolerant and susceptible lines. Based on the different gene expressions between the tolerant and susceptible lines, further studies are needed on breeding abiotic stress-tolerant lines.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.31-37
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• 1988

Germination and seedling elongation of soybeans [Glycine max. (L.) Merr., cults. Bangsakong, Hill, Paldalkong, Danyupkong, Baegwun-kong. Kwangkyokong, Changyupkong and Hwangkeumkong] were measured at two temperatures (15 and 30$^{\circ}C$) and four polyethylene glycol 10,000 (PEG) solutions (0, 20, 30 and 35g/100g-H$_2$O). Adjustments of PEG solution were based on water potentials of 0.0, -0.5, -1.1 and -1.5 MPa at room temperature. Observations were made at 3, 6, 9 and 12 days for 15$^{\circ}C$ and 1, 2, 3 and 4 days for 30$^{\circ}C$. Fifteen seeds of each cultivar were placed on Whatman No. 1 (9cm) filter paper in plastic pertridishes, and adjusted to 15 ml of the proper PEG solution supplemented with 0.2 percent thiram using automatic syringe. The dishes were covered with cap. The seeds were germinated at a continuous temperature of 15 or 30$^{\circ}C$ under dark conditions for programmed period. Seedling moisture content and seedling length of eight soybean cultivars decreased as PEG concentration increased both at 15 and 30$^{\circ}C$. Cultivar differences in seedling moisture content and seedling length were found among eight soybean cultivars at temperatures of 15 and 30$^{\circ}C$. Larger sized cultivar absorbed more moisture than samller sized cultivar. However, reverse results were obtained on the seedling moisture content of each of eight soybean cultivars. Cultiver Hill and Paldalkong showed greater seedling length than the other six cultivars from 20 to 30g/100g water of PEG concentrations both at 15 and 30$^{\circ}C$. The results of this study indicated that germination test of soybean seeds in aqueous solutions of PEG has potential for screening soybean cultivars for improved emergence during moisture stress.

• Journal of Animal Environmental Science
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• v.2 no.1
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• pp.41-52
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• 1996

This experiment was carried out to study the effect of sprinkler and fan cooling system on the physiological parameter, milk production and milk composition for Holstein cows in hot, humid climates. Thirty cows were assigned to one of two sections of open-sided loose barn. Water nozzles of sprinkler system were spaced in line at 1.2m intervals. Forced air was provided by 85cm diameter fans at rate of 3.4㎥/sec. The results obtained from these experiments are as follows: 1. There was no significant difference in meteorological data between control and fan + sprinkler cooling system(treatment group). 2. Skin temperature and rectal temperature of the treatment group were significantly lower than those of the control group (32.96 : 39.53$^{\circ}C$ vs 34.02 : 41.21$^{\circ}C$ respectively) (P<0.05). 3. Serum cortisol concentration of the treatment group(0.90$\mu\textrm{g}$/dL) was lower than that of control group(1.44$\mu\textrm{g}$/dL)(P<0.05). 4. Milk production of cows cooled with a sprinkler and fan cooling system was significantly higher than that of no cooling system (P<0.0l). 5. Lactose, protein and solid-not-fat content of milk were not changed by the treatments. Milk fat content of the control(3.23%) was low compared with the treatment group(3.38%). Somatic cell count was reduced by 26.63% in the treatment. The results indicate that a sprinkler and fan cooling systems can provide an effective means to relieve heat stress and enhance productivity of lactating Holstein cows during hot and humid summer season.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.57-67
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• 2020

Pinus densiflora is the most widely distributed tree species in South Korea. Its ecological and socio-cultural attributes makes it one of the most important tree species in S. Korea. In recent times however, the distribution of P. densiflora has been affected by dieback. This phenomenon has largely been attributed to climate change. This study was conducted to investigate the responses of growth and physiology of P. densiflora to drought and nitrogen fertiliz ation according to the RCP 8.5 scenario. A Temperature Gradient Chamber (TGC) and CO₂. Temperature Gradient Chamber (CTGC) were used to simulate climate change conditions. The treatments were established with temperature (control versus +3 and +5℃; aCeT) and CO₂ (control: aCaT versus x1.6 and x2.2; eCeT), watering(control versus drought), fertilization(control versus fertilized). Net photosynthesis (P_n), stomatal conductance (g_s), biomass and relative soil volumetric water content (VWC) were measured to examine physiological responses and growth. Relative soil VWC in aCeT significantly decreased after the onset of drought. P_n and g_s in both aCeT and eCeT with fertiliz ation were high before drought but decreased rapidly after 7 days under drought because nitrogen fertilization effect did not last long. The fastest mortality was 46 days in aCeT and the longest survival was 56 days in eCeT after the onset of drought. Total and partial biomass (leaf, stem and root) in both aCeT and eCeT with fertiliz ation were significantly high, but significantly low in aCeT. The results of the study are helpful in addressing P. densiflora vulnerability to climate change by highlighting physiological responses related to carbon allocation under differing simulated environmental stressors.

• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.13-20
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• 2015

This study was conducted to evaluate influence of short-term application of abscisic acid (ABA) in nutrient solution on growth and drought tolerance of tomato seedlings. The treatments included four ABA concentrations (0.5, 1, 2, $3mg{\cdot}L^{-1}$) and control (non-treatment) were applied to the nutrient solution in a hydroponic system. On the $5^{th}$ and $10^{th}$ day after growing in the nutrient solution containing ABA, seedlings were transferred to -5 bars of PEG-8000 in a growth chamber to induce water stress. Except for stem diameter and fresh and dry weight of root, there were no statistical differences in other growth parameters among control, 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments. Seedlings growths were strongly inhibited in nutrient solution containing 2 and $3mg{\cdot}L^{-1}$ of ABA. The root growth such as fresh and dry weigh of root, total root surface area, and average root diameter was slightly enhanced in $1mg{\cdot}L^{-1}$ of ABA treatment. The elevation of ABA concentrations in nutrient solution resulted in the decrease in transpiration rate and increase in stomatal diffusive resistance and leaf temperature of tomato seedlings. The initiations of seedling wilting after treating in -5 bars of PEG were delayed from 10 hrs in control to 30 hrs in ABA applied treatments. Additionally, the high percentages of recovered seedlings were observed in 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments after re-irrigation. Therefore, short-term application of $1mg{\cdot}L^{-1}$ of ABA in the nutrient solution stimulated the root growth and drought tolerance of tomato seedlings by delaying the start time of wilting point and enhancing the recovery after re-irrigation.