• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.778-784
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• 2017

We investigated the possibility of a bio-monitoring system for predicting toxic dinoflagellates (Genus Alexandrium) by the measuring shell valve movements(SVMs) of Pacific oyster, Crassostrea gigas (Mollusca: Bivalvia) using the Hall element sensor. We then described the SVMs of Pacific oyster exposed to the toxic algae under laboratory conditions. Pacific oyster used for experiment were fed Isochrysis galbana until they stabilized and kept under hunger conditions for three days to prevent the influence of food before the experiment. Pacific oyster were exposed to the toxic dinoflagellate, A. fundyense, and the potentially toxic dinoflagellate, A. affine. When Pacific oyster were exposed to A. fundyense, SVMs increased over 10 times/hr at low cell densities of 20 cells/mL. SVMs increased again at $14.1{\pm}5.7times/hr$ at 500 cells/mL, and $27.9{\pm}11.1times/hr$ at the high cell density of 5,000 cells/mL. However, in the presence of A. affine, SVMs increased at $6.7{\pm}3.9times/hr$ until 300 cells/mL, while they increased greatly to $15.3{\pm}10.8times/hr$ at 1,000 cells/mL. The SVMs of Pacific oyster indicated differences depending on species for toxic dinoflagellates. Therefore, the SVMs of Pacific oyster could be useful for A. fundyense, but would bedifficult to apply for A. affine.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.5
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• pp.371-377
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• 2009

In oxy-fuel combustion, $CO_2$ concentration in the flue gas may be enriched up to 95% owing to the gas recirculation. Under the high $CO_2$ concentration, the calcination characteristic of limestone is different from that of the conventional air combustion system. In this study, three types of limestone taken from different regions in Korea were used as $SO_2$ absorbent and their calcination characteristics depending on calcination temperature were investigated. The experiments were performed to examine the effects of operating variables such as absorbent species, reaction temperatures on the $SO_2$ removal efficiency and reacted limestone particles were captured to examine the sulfur contents. The degree of calcination and the specific surface area increased with calcination temperature and $SO_2$ removal efficiency increased with reaction temperature. The results showed remarkable difference in $SO_2$ removal efficiencies between the limestone types. The sulfur content of the reacted limestone with the highest $SO_2$ removal efficiency was about 10%.

• Journal of Korea Soil Environment Society
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• v.2 no.1
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• pp.21-34
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• 1997

Retention ponds have been dug along some of the motorways in France to minimize environmental pollution by preventing pollutants from spreading over the surrounding area. A series of studies have been conducted to determine the physicochemical characteristics of the particles settling down in such a pond to evaluate the effectiveness of the pond as a trap for heavy metals such as Pb, Zn and Cd. The highly contaminated roadside soil and the uncontaminated background soil were also studied for comparison. The settling particles exhibited heavy metal concentrations of 2 to 8 times as much as the background Sologne soil, depending on the metal species. However, the heavy metal concentrations in the roadside soil were 7 to 26 times higher than those in the· settling particles. Sequential extraction experiments illustrated that the highly contaminated roadside soil consisted mainly of the readily soluble fractions (FII, FIII and FIV) for all three heavy metals, but little W which is hardly soluble. The proportion of W considerably increased up to one third of the total in the settling particles for Pb and Zn. This result as well as the large concentration differences between the roadside soil and the settling particles indicates that most of the heavy metals were lost to the surroundings even before reaching the retention pond. Cd exhibited somewhat different behavior in that the most soluble FI, which is negligible for Pb and Zn, occupied as much as one fourth of the total in the roadside soil. In addition, FV for Cd did not increase in the settling particles.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.779-786
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• 2012

Many farmers have been seeking alternatives to chemical fertilizer for successful organic fruit production. This experiment was carried out to investigate the replaceability of chemical fertilizer by cover crop and slurry composting biofiltration (SCB) liquid manure (LM) application in pear orchard. Three treatments were contained in this experiment; cover crop only and cover crop + LM treatment, and control (chemical fertilizer application). Dry weight and mineral contents of gramineous cover crops were significantly increased in LM-combined treatments than that of leguminous species. Bulk density of soil was decreased in rye + LM and hairy vetch + LM treatments, compared with each cover crop treatment. Soil pH was lowest in fertilizer treatment and soil nitrate content became similar between treatments after rainy season. Available soil phosphate was lower in cover crop and cover crop + LM treatmemts than control, but exchangeable Mg was higher. The mineral content and net assimilation rate of leaves showed no difference between the treatments. As a result, it is suggested that the application of SCB liquid manure in pear orchard managed by cover crops is desirable to maintain the productivity by improving soil physical properties and potential nutrient recovery.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.329-338
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• 2006

Phylogenetic relationships and DNA polymorphism among local populations of the Korean native catfish species, Liobagrus mediadiposalis, have been investigated based on mitochondrial cytochrome b DNA sequences. As a result, three genetically distinct groups of local populations were recognized based on the phylogenetic tree constructed. The first group was called "Nakdong-river group" that included the local populations from Geumho-river, Gyeongho-river, and Deokcheon-river; the second one was "Geum-river group"; the third one was represented as "Seomjin-river group" that included the samples from Seomjin-river, Dongjin-river and Geokum-do. The phylogeny also implied that the ancestral group of L. mediadiposalis have first evolved to Nakdong-river group, and later two local populations (Geum-river and Seomjinriver group) were diverged from the other lineage. DNA polymorphisms we observed were 4.4~4.7% between Geum-river group and Seomjin-river group, 5.1~5.5% between Seomjinriver group and Nakdong-river group, and 5.5~5.7% between Nakdong-river group and Geumriver group. These results indicated the long period of geographic isolation due to the river system in Korea caused such high degrees of DNA polymorphisms between local populations of L. mediadiposalis.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1247-1255
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• 2016

Heparin binding proteins (HBPs) are produced by accessory glands. These are secreted into the seminal fluid, bind to the spermatozoa at the time of ejaculation, favour capacitation, acrosome reaction, and alter the immune system response toward the sperm. The present study was conducted with an objective to assess the effect of purified seminal plasma-HBPs (SP-HBPs) on cross bred cattle bull sperm attributes during two phases of cryopreservation: Pre freezing and freezing-thawing. SP-HBPs were purified from pooled seminal plasma by heparin affinity chromatography. Three doses of SP-HBPs i.e. 10, 20, $40{\mu}g/mLs$ semen were standardized to find out the optimum dose and $20{\mu}g/mLs$ was found to be an optimum dose. Semen as such and treated with SP-HBPs was diluted with sodium citrate-egg yolk diluter and cryopreserved as per the standard protocol. Sperm parameters i.e. motility, viability, Hypo-osmotic swelling test (HOST), acrosome damage, in vitro capacitation and lipid peroxidation were evaluated in SP-HBP treated and untreated (control) semen at both phases of cryopreservation. A considerable variation in percent sperm motility, viability, membrane integrity (HOST), acrosome damage, acrosome reaction and lipid peroxidation was observed at both phases among the bulls irrespective of the treatment. Incubation of neat semen with $20{\mu}g/mL$ SP-HBP before processing for cryopreservation enhanced the average motility, viability, membrane integrity by 7.2%, 1.5%, 7.9%, and 5.6%, 6.6%, 7.4% in pre-frozen and frozen-thawed semen in comparison to control. There was also an average increase of 4.1%/3.9% in in vitro capacitation and acrosome reaction in SP-HBPs-treated frozen-thawed semen as compared to control. However, binding of SP-HBPs to the sperm declined acrosome damage and lipid peroxidation by 1.3%/4.1% and 22.1/$32.7{\mu}M$/$10^9$ spermatozoa in SP-HBP treated pre-frozen/frozen-thawed semen as compared to control, respectively. Significant (p<0.05) effects were observed only in motility, HOST and in vitro acrosome reaction. It can be concluded that treatment of neat semen with SP-HBPs before cryopreservation minimized the cryoinjury by decreasing the generation of reactive oxygen species.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.313-323
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• 2016

Water temperature affects physical and biological processes in ecologies on river system and is important conditions for growth rate and spawning of fish species. The objective of this study is to compare models for water temperature during the summer season for the Fourchue River (St-Alexandre-de-Kamouraska, Quebec, Canada). For this, three different models, which are CEQUEAU, Auto-regressive Moving Average with eXogenous input and Nonlinear Autoregressive with eXogenous input, were applied and compared. Also, future water temperature in the Fourchue river were simulated and analyzed its result based on the CMIP5 climate models, RCP 2.6, 4.5, 8.5 climate change scenarios. As the result of the study, the water temperature in the Fourchue river are actually changed and median water temperature will increase $0.2{\sim}0.7^{\circ}C$ in June and could decrease by $0.2{\sim}1.1^{\circ}C$ in September. Also, the UILT ($24.9^{\circ}C$) for brook trout are also likely to occurred for several days.

• Fisheries and Aquatic Sciences
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• v.19 no.8
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• pp.32.1-32.6
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• 2016

A feeding trial was conducted to evaluate the effects of two different sizes of extruded pellets (EP) ($EP_1$ - 3 mm or $EP_2$ - 5 mm) and a moist pellet (MP) in olive flounder, Paralichthys olivaceus, reared in semi-recirculation system. A total of 450 fish with an average initial weight of $5.0{\pm}0.2g$ (mean ${\pm}$ SD) were fed one of the three experimental diets in triplicate groups. At the end of a 6-week feeding trial, weight gain, specific growth rate, and feed efficiency of fish fed EP diets were significantly higher than those of fish fed MP (P < 0.05). Water quality parameters like turbidity, total ammonia nitrogen, and total phosphorous from tanks of fish fed $EP_1$ and $EP_2$ were significantly lower than those from tanks of fish fed MP. Blood plasma glutamic oxaloacetic transaminase and glucose concentration were significantly higher in fish fed MP diet compared to fish fed EP diets (P < 0.05). Whole body crude protein contents in fish fed EP diets were higher than those from the fish fed MP diet. Whole body amino acid content like threonine, aspartic acid, serine, tyrosine, and cystine were found to be significantly higher in fish fed EP diets than those in fish fed MP diet. In considering overall performance of olive flounder, $EP_2$ diet could be recommended for the successful aquaculture of this important fish species.

• Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.63-70
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• 2010

Two feeding experiments were conducted to investigate the effects of dietary genetically modified (GM) soya and com on growth performance, feed utilization and body composition of juvenile olive flounder, Paralichthys olivaceus and rockfish, Sebastes schlegelii. For each fish species, four isonitrogenous (50% crude protein) and isocaloric (4.1 kcal/g) diets (designated as nGM soya, GM soya, nGM com and GM com) were formulated to contain 20% non-GM (nGM) and GM soya and com. Thirty olive flounder (initial body weight, 15.4${\pm}$0.4 g) and fifty rockfish (initial body weight, 3.1${\pm}$0.02 g) were distributed in each 400 L tank (200 L water) in a flow through system. Each experimental diet was fed to triplicate groups of fish to visual satiation, twice a day (9:00 hand 17:00 h) for 6 weeks. Growth performance was measured every three weeks. No effects of GM feedstuffs on survival were observed. Dietary inclusion of GM feedstuffs did not affect growth performance and feed utilization of fishes, except for rockfish fed GM com. Rockfish fed the GM com diet showed higher weight gain, daily feed intake and daily protein intake than did fish fed the nGM com diet, but no significant differences were observed in final body weight between the dietary treatments. Condition factor, hepatosomatic index, visceral somatic index and body composition were not altered by the inclusion of GM feedstuffs. These results indicate that dietary inclusion of GM soya and com could have no effects on growth performance and feed utilization of juvenile flounder and rockfish. Lower weight gain and feed intake in flounder and rockfish fed the diets containing 20% soya were likely due to anti-nutritional factors, rather than transgenic factors in the feedstuffs. Dietary inclusion of GM soya and com at the level tested did not alter the body composition of fishes. Further studies to investigate the effects of GM feedstuffs on health conditions and the development of fishes, as well as those of residue of transgenic fragments in ambient environments and in animals are necessary for safe use of the ingredients in aquaculture.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.3
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• pp.119-126
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• 2019

For this purpose, research was made to look into the style, material, organization, and legal as well as institutional system of the bonsai industry in the three countries. In order to understand what significance it has and how it has changed historically, related literature was surveyed and questionnaires were distributed to the concerned people to collect the data needed for them to plan bonsai industry. The results of the survey are as follows. Analysis of awareness of bonsai culture, respondents replied that the motive and purpose of bonsai is because they like flower trees, and the technical information about bonsai is usually obtained by visits to bonsai gardens. The analysis revealed that respondents usually join more than one bonsai club and are active more than once a month, which means longer than 4 hours each month, and their activities are more frequently in the metropolitan area. From the analysis of preference for bonsai culture, it was made known that the favorite bonsai size is less than middle one(20~50cm), the characteristics of the favorite species are beauty. A research and analysis of bonsai-related technical education found that bonsai is trimmed manually in general, bonsai experts are usually kept in contact with, and the bonsai technique is learned through interaction with the experts.