• The Korean Journal of Malacology
• /
• v.25 no.2
• /
• pp.93-96
• /
• 2009

Unexpected mass mortality has been one of the drawbacks in front of the stable production of Japanese scallop (Patinopecten yessoensis) on the Gangwon coasts of the East Sea. The preliminary data from our routine observation revealed that the mortality appeared to be related to variation of water temperature in the farming site and the degree of the mortality was dependent on scallop strain. The present study performed to verify the preliminary findings exhibited that the mortality was closely related to daily temperature variation rather than monthly variation. Daily temperature variation was particularly damageable to the scallop during the temperature elevation period. Scallops from hatchery seeds (Chinese strain) were more tolerant against the temperature variation over those from wild seeds. The hatchery scallop gain of the temperature tolerance was probably due to their larval experience to higher temperature in the hatchery as well as their maternal genetic acclimation to upper temperature extreme of the Chinese environment which was recently found.

• Archives of Craniofacial Surgery
• /
• v.16 no.2
• /
• pp.73-79
• /
• 2015

Background: Alprostadil and sildenafil are known vasodilators used independently to improve flap survival in animal models. In this study, we investigate whether these agents act synergistically to decrease flap necrosis in rat models. Methods: After acclimation period, 4 groups of 10 male white rats were given a modified McFarlane skin flap. The postoperative treatment included saline control (Group A), sildenafil citrate-only (Group B), alprostadil-only (Group C), and both sildenafil and alprostadil (Group D). The flaps were observed on postoperative days 1, 3, 5 and 7. The animals were euthenized on postoperative day 7, and the flaps were evaluated for inflammation and neovascularization. Results: At each observation, the mean necrotic index was significantly lower for all three treatment groups (Groups A, B, C) and was the lowest for the combined treatment group. On histologic evaluations, combined treatment was associated with decreased inflammation and increased capillary vessel formation, when compared with control group. Conclusion: Both sildenafil-only and alprostadil treatments were independently associated with increased flap survival rate. Sildenafil citrate and alprostadil had a synergistic effect in increasing flap survival rate.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.54 no.5
• /
• pp.676-684
• /
• 2021

Euryhaline teleost have extraordinary ability to deal with a wide range of salinity changes. To study the seawater adaptability of rainbow trout Oncorhynchus mykiss (body weight 638±54 g, length 38.6±2 cm) to salinity increase fish were transferred from freshwater to 7, 14, 21, 28 and 32 psu and checked for mortality over 5 days. No mortality was observed in 0-32 psu. In fish transferred to 0-32 psu, blood osmolality was maintained within physiological range. The changes of serum enzyme activities (aspartate transaminase, AST and alanine transaminase, ALT) showed no significant level during experimental period. To explore the underlying molecular physiology of gill and kidney responsible for body fluid regulation, we measured mRNA expression of five genes, Na⁺/K⁺/2Cl^- cotransporter1 (NKCC1), aquaporin3 (AQP3), cystic fibrosis transmembrane conductance regulator (CFTR), glucocorticoid receptor (GR) and growth hormone receptor (GHR) in response to salt stress. Based on our result, rainbow trout could tolerate gradual transfer up to 32 psu for 5 days without mortality under physiological stress. This study suggests to alleviate osmotic stress to fish, a gradually acclimation to increasing salinity is recommended.

• Journal of Aquaculture
• /
• v.21 no.2
• /
• pp.63-69
• /
• 2008

We isolated complementary DNA(cDNA) encoding prolactin receptor(PRLR) from gill of black porgy Acanthopagrus schlegeli. Its PRLR cDNA consists of 1,611 base pairs and encodes the protein of 536 amino acids. To investigate the osmoregulatory abilities of black porgy in different salinities(35, 10 and 0 psu), we examined the expression of PRLR mRNA in osmoregulatory organs(gill, kidney and intestine) using reverse transcription(RT)-PCR. In gill and intestine, PRLR mRNA levels were high in 10 psu, and then decreased in 0 psu, but there is no changes in kidney. Also, plasma osmolality, $Na^+\;and\;Cl^-$ levels decreased during the experimental period. These results suggest that PRLR plays an important role in hormonal regulation in osmoregulatory organs during freshwater acclimation, thereby improving the hyper-osmoregulatory ability of black porgy in hypoosmotic environments.

• Journal of Environmental Health Sciences
• /
• v.21 no.4
• /
• pp.1-9
• /
• 1995

This study was carried to investigate the biodegradability of phenol in the wastewater with the two sludge blanket-packed bed reactor in series. Each reactor had a dimension of 0.09 m i.d. and 1.5 m height and consisted of two regions. The lower region was a sludge blanket of 0.5 m height and the upper region was a packed-bed of 1 m height. The packed bed region was charged with ceramic raschig rings of 10 mm i.d., 15 mm o.d. and 20 mm length. The reactors were operated at 35$\circ$C and the hydraulic retention time(HRT) was maintained 24 hours. The synthetic wastewater composed of glucose and phenol as major components was fed into the reactor in a continuous mode with incereasing phenol concentration. In addition, the nutrient trace metals($Na^+, Mg^{2+}, Ca^{2+}, PO_4^{3-}, NH_4^+, Co^{2+}, Fe^{2+}$ etc.) were added for growing anaerobes. The phenol concentration of the effluent, the overall gas production, the composition of product gas, the efficiency of COD reduction and the duration of acclimation period were measured to determine the performance of the anaerobic wastewater treatment system as the phenol concentration of the influent was increased from 600 to 2400 mg//l. Successfully stable biodegradation of phenol could be achieved with the anaerobic treatment system from 600 to 1, 800 mg/l of the influent phenol concentration. The upper level of influent phenol loading was high enough to meet most of the practical requirement. The duration of acclimation increased with the phenol loading. At steady state of the influent phenol concentration of 1800 mg/l, the treatment performance indicated the phenol reduction efficiency of 99%, the COD reduction efficiency of 99% and the gas production rate of 37 l/day. At the influent phenol concentration of 2400 mg/l, however, the operation of the treatment system was noted unstable. While the concentration of methane in biogas decreased with increasing the influent phenol loading, the carbon dioxide was increased. However, the concentration of hydrogen was varied negligibly. The concentration of methane was high enough to be used as a fuel. As a result, it is suggested that anaerobic phenol wastewater treament was economical in the sense of energy recovery and wastewater treatment.

• Journal of Aquaculture
• /
• v.20 no.4
• /
• pp.226-231
• /
• 2007

We investigated survival and osmolarity, oxygen consumption, amonia extetion and filtration rates associated with physiological responses of the tunicate Halocynthia roretzi salinity changes. Acclimation times for osmolatity in different salinities took $20{\sim}26$ hours in 60% SW (19.8 psu) and $20{\sim}25$ hours in 80% SW (26.4 psu), while their times took $7{\sim}8$ hours in 110% SW (36.3 psu). Accordingly, acclimation times for high salinities were faster than those for low salinities. Survival (%) was more than 80% at salinity over 26.4 psu, and 6 $days-LS_{50}$ was 25.4 psu. physiological responses such as oxygen consumption, amonia excretion and filtration rates of H. roretzi showed more clear reactions in the longer exposure period (four days after exposure) than that in the beginning of the exposure. To sum up the results, the tunicate might be stressed from the beginning of the exposure in low salinity.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.6
• /
• pp.447-451
• /
• 2003

When sowing green peas in the autumn, proper seedling stands and growth quantity should be secured before winter begins. Also, for proper acclimatization, injuries caused by low temperatures, frost or high temperatures in the P.E. film during mulching, should be avoided during the regeneration period; that being early spring. The days required for growth in each stage in Yeosu are shorter than those in Naju because Yeosu has high temperatures during the growth period. Furthermore, in Yoesu, it was observed that there were more effective branches as well as effective and attached node positions on the branches. The first pods on the main stems and effective branches were observed to be higher than those in Naju. The number of pods per plant and the number of seeds per pod in Yoesu was greater than for those in Naju and the pod length was longer as well. Considering the missing plant rate, growth, and green pod yield, the optimum sowing date for the green pea was mid-November in both location. The stable acclimatizing date for the green pea was early March when the highest yield can be acquired due to a lot of effective branches and pods per plant and with the lowest missing plant rate and rate of injury in acclimatization.

• Journal of Acupuncture Research
• /
• v.37 no.2
• /
• pp.110-117
• /
• 2020

Background: The aim of this pilot study was to assess the safety and dosing of scolopendrid pharmacopuncture (SPP). Methods: A total of 40 healthy Sprague-Dawley rats (males and 20 females 20) were selected following a 7-day inspection and acclimation period. SPP was administered via intramuscular injection, over a 2-week period using 3 doses including a high-dose [0.84 mg of scolopendrid per kg of body weight (BW)], a med-dose (0.42 mg/kg BW), and a low-dose (0.21 mg/kg BW). The control group was injected with sterile water into the muscles. Unusual changes caused by administration of the test substance were observed. Weight, feed intake, organ weight, and hematological examinations were compared among the groups. Using the SPSS statistical program, Levene's test was performed to evaluate the homogeneity of variances, and a one-way ANOVA test was subsequently performed to assess the significance between each test group. Results: During the experiment no animals died. Weight change, food consumption, organ weight, hematological test, and blood biochemical tests showed no significant differences in the treatment groups compared to controls. Conclusion: No toxicological changes related to the administration of test substances were observed. Therefore, the LD₅₀ (lethal-dose that kills 50%) of scolopendrid pharmacoupuncture in rats was greater than 0.84 mg/kg.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.45 no.5
• /
• pp.430-437
• /
• 2012

The effects of low temperature and starvation on the physiochemical characteristics of the muscle of the olive flounder Paralichthys olivaceus, were examined. Fish were deprived of feed for 28 days at 2, 4, 6, 8, 10, 12, and $20^{\circ}C$ in order to establish suitable conditions for live fish transportation. Throughout most of the 4 weeks of feed restriction, the physiochemical characteristics of the muscle of olive flounder were found to be dependent on the acclimation temperature. The breaking strength of muscle did not show a significant reduction during feed restriction at 2 and $4^{\circ}C$. With increasing temperatures, however, the breaking strength of muscle differed significantly according to the individual and feed restriction period (P<0.05). The moisture content in muscle acclimated at 10, 12, and $20^{\circ}C$ increased steadily over the feed-restriction period, while the crude lipid content decreased during the same period (P<0.05). At water temperatures above $2-8^{\circ}C$, no significant differences were shown during the same period. After it reached 6, 8, 10, 12, and $20^{\circ}C$, the muscle had an accumulation of lactate, and a loss of ATP. There was no change in the lactate or ATP content during the feed restriction period at 2 and $4^{\circ}C$, although there were differences among the water temperature groups. These results clearly show that temperature can have an important influence on the of muscle of physiochemical characteristics of muscle during live fish transportation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.2
• /
• pp.168-172
• /
• 1996

The soil moisture content and its relation to plants may be important in determining the crop growth and yield. The present study was undertaken to evaluate the leaf water potential and photosynthetic activity in soybean plants as affected by the timing of soil water stress. The soybean variety, 'Tachinagaha', was grown in a pot. The 15 day-old seedlings were subject to the three levels of soil moisture content(25, 40 and 55%) for 25 days. Then the treated soybean plants were placed again at the level of 25% soil moisture content for 25 days, and were compared with the control which was well-watered at 40% level for whole growth period. Soybean plants grown under continuous drought showed higher apparent photosynthetic rate(AP) than those under well-watering /drought in the first /second water treatment, suggesting that AP was adjusted after previous acclimation to drought. Over a wide range of photosynthetic photon flux densities(PPFD), drought or excessive water stress resulted in the decrease in AP when compared with the control. AP and stomatal conductance were decreased in soybean plants subject to water deficit stress, suggesting that AP and stomatal conductance were more sensitive to drought than excessive water stress.