• Korean Journal of Environment and Ecology
• /
• v.7 no.1
• /
• pp.10-21
• /
• 1993

Artificial acid rain (pH 3.0, 4.0 and 5.0) and ground was treated on the seeded pots of 4 species to examine its effects on germination and survival rate, seedling growth and contact angles on needle surface. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water (pH 6.5) was used as control. Artificial acid rain was sprayed to seeded pots two or three times per week for growing season, one times per week for winter seasons. About 5mm of artificial acid rain was treated each time from early April, 1991 to early October, 1993. Germination and survival rate, soil acidity, seedling growth and contact angles on the needle surface were measured and compared among the treatments. The results were summarized as follows ; Artificial acid rain might have positive effects on growth-related characteristics of the seedlings in the first and second year of acid rain treatment, and the effects were differed among four species. All growth-related characteristics of the seedlings in third year, however, decreased with decrease of pH values of artificial acid rain. This was considered to the results of acidic accumulation over soil buffer capacity. Needle injury and biomass (defoliation) was correlated with the pH values of artificial acid rain, and this character might be a good criteria for early diagnosis of acid rain injury. The differences of soil acidity were significant among the treatments for all species. Contact angles between needle surface and water droplet decreased with decrease of pH values of artificial acid rain. Measuring and comparing contact angles might be very good criteria for early diagnosis of acid rain injury.

• Korean Journal of Heritage: History & Science
• /
• v.37
• /
• pp.327-348
• /
• 2004

In this study, after analyzing several local climate characteristics of South Korea, I validated distribution, invasion, foraging, underground activities, attack season as ecological characteristics and also temperature, relative humidity, and tree species as preference characteristics of Korean termites (Reticulitermes speratus kyushuensis Morimoto). Especially, southern part of the Korean peninsula is a suitable area for inhabitation and motion of termites holding same ecological characteristic like R. speratus kyushuensis. Busan is a neighboring district at field distribution north limiting temperature of Coptotermes formosanus Shiraki and Chuncheon is a passing area through the Korean Peninsula of field distribution north limiting temperature of Reticulitermes speratus Kolbe. The termite attack of wood devices was about 34.5% for 3 years in the forest of Jongmyo. Although the attack rate of termite increased each year, the detection rate decreased and the missing rate was high by degrees. I confirmed a foraging habits which is a part of termite colony was a role of continuous decomposition and another was a role of new food hunt as experimental results. The foraging termites were found under ground at Jongmyo in Seoul from April to November in the 2001 and the most active period was on July and August. The termite invasion rate of bait station increased in every monitoring. Through the increasing attack rate of bait station during 2nd monitoring (November, 2000) and 3rd monitoring(March, 2001), I confirmed that termites moved into the deep underground in winter, and were working continuously to forage. R. speratus kyushuensis inhabiting at the Korean Peninsula is a species which has food consumption rate with higher temperature. The termite revealed the greatest amount of food(filter paper) at $30^{\circ}C$(90% RH), but showed increasing death rate at over $32^{\circ}C$. Also, survival rate of this termite was 97% at 84% RH($30^{\circ}C$), but killed 100% at 52% RH($30^{\circ}C$) and 70% RH($30^{\circ}C$). For wood feeding, this was observed the preference in a pine tree(Pinus densiflora) above all others. Survival of termites was high(87%) at a pine tree, but low(13.5%) at a paulownia tree(Paulownia coreana). In this study, I presented the biological characteristic of termite(R. speratus kyushuensis Morimoto) and confirmed the deterioration degree of termite on wooden cultural heritage in Korea. Depending on climate and soil temperature, each area in the southern part of the Korea Peninsula, has some different active period and different distribution of R. speratus kyushensis. With these results, I expect that this report helps to prepare the integrated pest management(IPM) of the termite on wooden cultural heritage in Korea, and it may help to reduce the economical loss from termite damage in Korea.

• Journal of the Korean Society of Floral Art and Design
• /
• no.37
• /
• pp.157-166
• /
• 2017

To select fruit trees for urban garden with Elaeagnus umbellata var. coreana, Malus domestica 'Alps Otome', Prunus mume, Ribes nigrum, Rubus fructicosus, and Vaccinium corymbosum 'Reka', growth characteristics of these 6 species were compared and effect of trickle irrigation and shading on the growth of these fruit trees were investigated that these treatments were carried out how much these trees are endurable exposed to improper conditions. After passing the winter, E. umbellata var. coreana, M. domestica 'Alps Otome', P. mume, and V. corymbosum 'Reka' showed the highest survival rate, in contrast to R. nigrum with the lowest of 56.0%. In 9 months after planting, the hight growth rate of 62.3% was shown in P. mume but that of E. umbellata var. coreana was stagnant during experimental period. Flowering rate over 80.0% were shown in E. umbellata var. coreana, M. domestica 'Alps Otome', R. fructicosus, and V. corymbosum 'Reka'. On the other hand, R. nigrum has not ever flowering branches. Other species except E. umbellata var. coreana and R. nigrum have about 10 days in flowering duration. After flowering, fruition rate has shown significant difference among 6 species. As a result of both treatment of trickle irrigation and shading, leaf area and leaf weight of E. umbellata var. coreana, M. domestica 'Alps Otome' significantly inceased with treatments that have not affected other species. Based on these result, it is possible to deploy suitable fruit trees to specific garden condition after selecting various fruit trees.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.4
• /
• pp.339-343
• /
• 2000

When plants are exposed to subfreezing temperatures ice crystals are forming within extracelluar space in leaves. The growth of ice crystal is closely related to the degree of freezing injury. It was shown that an antifreeze protein binds to an ice nucleator through hydrogen bonds to prevent growth of ice crystal and also reduces freezing damage. The antifreeze proteins in plants are similar to PR proteins but only the PR proteins induced upon cold acclimation were shown to have dual functions in antifreezing as well as antifungal activities. Three of the genes encoded for CLP, GLP, and TLP were isolated from barley and Kentucky bluegrass based on amino acid sequence revealed after purification and low temperature-inducibility as shown in analysis of the protein. The deduced amino acid of the genes cloned showed a signal for secretion into extracellular space where the antifreezing activity sup-posed to work. The western analysis using the antisera raised against the antifreeze proteins showed a positive correlation between the amount of the protein and the level of freeze tolerance among different cultivars of barely. Besides it was revealed that TLP is responsible for a freeze tolerance induced by a treatment of trinexapac ethyl in Kentucky bluegrass. Analysis of an overwintering wild rice, Oryza rufipogon also showed that an acquisition of freeze tolerance relied on accumulation of the protein similar to CLP. The more direct evidence for the role of CLP in freeze tolerance was made with the analysis of the transgenic tobacco showing extracellular accumulation of CLP and enhanced freeze tolerance measured by amount of ion leakage and rate of photosynthetic electron transport upon freezing. These antifreeze proteins genes will be good candidates for transformation into crops such as lettuce and strawberry to develop into the new crops capable of freeze-storage and such as rose and grape to enhance a freeze tolerance for a safe survival during winter.

• Korean Journal of Veterinary Service
• /
• v.26 no.2
• /
• pp.135-144
• /
• 2003

Fowl typhoid is a septicemic disease of turkeys and chickens. The antigen is Salmonella(S) gallinarum, which cross-reacts with S pullorum because of common antigen. The organism is maintained in the ovary of carrier birds and transmitted vertically in the york. It is also transmitted horizontally through feces and broken eggs. The symptoms are weakness, drowsiness, wing drooping, hyperexcitability, paresis and diarrhea. In the many cases, the birds are found dead in the morning before any symptoms have been noticed. this experiment was carried out to investigate the characteristics of S gallanarum and scrutinized about the control systems. 1. Fowl typhoid was came about in the winter than the other seasons. The average of mortality was 46.3%. And it was came about not only adult poultry but also chicks. 2. S gallinarum was isolated from liver and spleen in infected chickens. Total isolated strains were 60. 3. The organisms were all extinct at 60$^{\circ}C$, 30mins. 4. A survival rate was higher in underground water than a secondary distilled water. It was detected in underground water until 30 days. 5. When being exposed to the solar light, it became extinct almost within 24 hours. 6. It was survived in a refrigerator until 12 months. 7. It was extinct among 5 mins in 0.1% phenol and 2% formalin. 8. When the cultured organism fluid was inoculated in SD-rat abdominal cavity, rat died within 24 hours. 9. Pullorum-typhoid related program must disciplines in order to destroy the fowl typhoid, and breeding system must be converted to cage system.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.6
• /
• pp.747-752
• /
• 2011

The parrotfish Oplegnathus fasciatus is a sub-tropical species that is difficult to culture during the winter in South Korea. As a result, a recirculating aquaculture system (RAS) was developed to rear parrotfish. This study investigated the effects of stocking density and dissolved oxygen (DO) concentration on the growth and hematology of the parrotfish in the RAS. The experimental stocking densities were 5 (SD05), 10 (SD10), 15 (SD15), and 20 kg/m3 (SD20) total body weight to tank water volume. As the stocking density increased, the mean weight gain, feed efficiency, and specific growth rate tended to decrease. However, SD10 and SD15 did not differ statistically from SD05 in feed efficiency (P>0.05). Although better growth was achieved in SD05, SD10 and SD15 appeared to be acceptable, practically and economically, in terms of feed efficiency. The experimental DO concentration ranges were 3-4 (DO3), 5-6 (DO5), and 7-8 mg/L (DO7). The mean weight gain and survival tended to increase with the DO concentration, but there were no differences among treatments (P>0.05). Although the feed efficiency did not differ among the treatments, the specific growth rates and daily feed intake increased with the DO concentration and were the highest in DO7 (P<0.05). The cortisol concentration was the highest in DO3 (P<0.05), while there was no difference between DO5 and DO7 (P>0.05).

• Journal of agriculture & life science
• /
• v.44 no.6
• /
• pp.61-67
• /
• 2010

Six evergreen ground-cover species including Ajuga reptans, Carex morrowii 'Variegata', Dianthus 'Night Star', Hedera helix 'Ivalace', Pachysandra terminalis, and Sedum rupestre, were tested for cold acclimation with three different light treatments (0, 30, and 70% of shading, respectively) to select potential candidates for over-wintering in central Korea. Among those species, Ajuga reptans, Carex morrowii 'Variegata', and Sedum rupestre performed well, which had more than 50% of survival rate in all light conditions. However, Dianthus 'Night Star' had less than 40% under any light treatment and the other two species, Hedera helix 'Ivalace' and Pachysandra terminalis, survived more than 40% only with 70% of shading condition. These results imply that those candidate species having less cold hardness in central Korea could have the potential to could over-winter as long as a proper light condition is provided.

• Fisheries and Aquatic Sciences
• /
• v.8 no.3
• /
• pp.138-141
• /
• 2005

This study was conducted to investigate the effect of partially substituting meat meal for fish meal on the growth and body composition of juvenile olive flounder Paralichthys olivaceus during the winter season. Twenty-five fish (initial body weight, 23 g) were distributed into twelve 250 L flow-through tanks. Four experimental diets were prepared in triplicate: the control, MM20, MM40, and MM60 diets. Sixty percent mackerel meal was used as the primary protein source in the control diet. Meat meal was substituted for 20, 40, and 60$\%$ of the mackerel meal in the MM20, MM40, and MM60 diets, respectively. Survival was not significantly affected by the experimental diets. However, the weight gain and specific growth rate of fish fed the control, MM20, and MM40 diets were significantly higher than those of fish fed the MM60 diet (P<0.05). The feed efficiency ratio of fish fed the control, MM20, and MM40 diets was significantly higher than that of fish fed the MM60 diet (P<0.05). The protein efficiency ratio for fish fed the control diet was significantly higher than that for fish fed the MM40 and MM60 diets (P$\%$ substitution of meat meal for fish meal in the diet could be implemented without a reduction in growth or deterioration of the feed efficiency of juvenile olive flounder during the winter season.

• Korean Journal of Ichthyology
• /
• v.31 no.4
• /
• pp.201-207
• /
• 2019

Temperature is one of the most important criteria considered in species preference for aquaculture. Acute drop in temperature during winter is a cause of disease and mass mortality in farmed fish. This study was carried out the low water temperature tolerance, oxygen consumption, hematologic and histological responses to use as basic data for the management of fish farming which frequently cause death due to winter water temperature drop. Low-lethal water temperature for 4 days of file fish Thamnaconus modestus (4day-LT₅₀) was 6.97℃ (6.69~7.27℃). Oxygen consumption rate decreased with decreasing water temperature, showing a significant difference between water temperatures. SOD activity increased significantly at 6℃ experimental group than control group (10℃) (p<0.05), but CAT did not show any significant difference between experimental temperatures (p>0.05). Cortisol increased with decreasing experimental water temperature compared to control group. Histological changes in the liver include decreased blood vessels in the blood vessels, proliferation of acid cells, condensation of the nucleus, atrophy of pancreatic exocrine gland cells, and enzyme source granules.

• Korean Journal of Ichthyology
• /
• v.28 no.1
• /
• pp.1-8
• /
• 2016

This study was conducted to investigate the physiological responses of sevenband grouper, Epinephelus septemfasciatus at low temperature condition in winter season. Water temperature was dropped from $12^{\circ}C$ to $5^{\circ}C$ by two different interval (interval I: $-1^{\circ}C/24h$ and interval II: $-1^{\circ}C/8h$). The experimental fishes were exposed for 9 days at each water temperature condition, and were observed survival rate. The blood sample was collected from fishes for analysis of cortisol, glucose, total protein (TP), and electrolytes ($Na^+$, $Cl^-$, $K^+$). Mortality of fish was not observed until $5^{\circ}C$. The mortality (12 individuals) began after 170 h and all fish were death after 174 h in interval I case, whereas the mortality (9 individuals) began after 72 h and all fish were death after 76 h in interval II case. Little different was observed in the physiological responses, but trend was similar between two intervals. The physiological metabolism of plasma cortisol and glucose were increased rapidly, and swimming ability and respiration response was faster at $7^{\circ}C$. This result means that the critical temperature of sevenband grouper was $7^{\circ}C$ at low water temperature condition.