• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.902-908
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• 2017

To determine the horizontal and temporal distribution of firefly squid, Watasenia scintillans (W. scintillans), larvae, we conducted surveys using IKMT (mesh size: $500{\mu}m$) and CTD (SBE9plus) with Fisheries Research Vessel (FRV, TAMGU 21) in the southern part of the East Sea in summer (August) and autumn (September and November) 2015. A total of 238 larvae, ranging in mantle length (ML) from 0.6 mm to 18.5 mm, were collected at 28 stations. Abundance and larval distribution density were significantly higher in summer than in autumn during the study period. Especially, the highest density of W. scintillans was observed in the coastal waters of the East Sea from Pohang to Pyunghae where cold water masses were distributed in summer. Optimum embryo survival temperature ($6-16^{\circ}C$) 40 to 180 m depth ranges for stations which larvae were collected.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.337-343
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• 2008

This study was conducted to investigate the distribution pattern, ecological characteristics and life cycle of the Black Soldier Fly (Hermetia illucens, BSF). The BSF was widely distributed throughout Korea. The insect was mainly found in the vicinity of and in cattle sheds, manure sheds, living waste dump grounds, and food waste dump grounds. Developmental characteristics of the BSF are as follows: the egg was long oval shaped of 887 ${\mu}m$ in the major axis and 190 ${\mu}m$ in the minor axis; it weighed 24 ${\mu}g$. Female oviposited ca. 1,000 eggs on average; eggs hatched in 81 hours under laboratory condition ($27^{\circ}C$, 60% R.H.). The duration of the larval stage was approximately $15{\sim}20$ days. The size of the last instar larvae was 21 mm. The cuticle of the pupae gradually acquired red-brown color and the size of them was 19 mm. The pupal stage was shorter for females (16 days) than males (15 days). Adults were sized about $13{\sim}20$ mm long and black-colored. The life span of adult insects was $5{\sim}8$ days for the first generation (June${\sim}$July), $7{\sim}10$ days for the second generation (Aug.${\sim}$Sept.), and $13{\sim}18$ days for the third generation (Sept.${\sim}$Oct.). Mating started on the next day of emergence and actively occurred at the third day after emergence. Mating mostly occurred between 10:00 and 16:00 during which light intensity is highest. Egg-laying started on the third day and was most frequent from the fourth to the sixth day after emergence. Similar to mating time, females oviposited mostly between 10:00 and 16:00.

• Korean Journal of Poultry Science
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• v.7 no.2
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• pp.54-76
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• 1980

A survey was conducted to determine the status of health and productivity of poultry farms in Korea. Area included Was Kyunggido where exist nearly 50% of national poultry population. From this area, 41 layer and 34 broiler farms covering 21 Countries were selected randomly for the survey. When farms were divided in the operation size, 95.1% of layer and 82.3% of broiler farms were classified as business or industrial level while the rest were managed in a small scale as part time job. Generally layer farms had been established much earlier than broiler farms. Geographically 10.7% of layer farms were sited near the housing area such as field foreast and rice field. No farms were located near the seashore. The distance from one farm from the other was very close, being 80% of the farms within the distance of 1km and as many as 28% of the farms within loom. This concentrated poultry farming in a certain area created serious problems for the sanitation and preventive measures, especially in case of outbreak of infectious diseases. Average farm size was 5,016${\times}$3.3㎡ for layers and 1,037${\times}$3.3㎡ for broilers. 89.5% of layer ana 70.6% of broiler farms owned the land for farming while the rest were on lease. In 60% of layer farms welters were employed for farming while in the rest their own labour was used. Majority of farms were equipped poorly for taking necessary practice of hygiene and sanitation. The amount of disinfectant used by farms was considerably low. As many as 97.6% of lave. farms were practised with Newcastle(ND) and fowl pox(F$.$pox) vaccine, whereas only 43.6% and 5.1% of broiler farms were practised with ND and F$.$pox vaccine, respectively. In 17-32.7% of farms ND vaccine was used less than twice until 60 days of age and in only 14.6% of farms adult birds were vaccinated every 4months. Monthly expense for preventive measures was over 200,000W in 32% of farms. Only 4.9-2.7% of vaccine users were soaking advice from veterinarians before practising vaccination, 85% of the users trusted the efficacy of the vaccines. Selection of medicine was generally determined by the farm owner rather than by veterinarans on whom 33.3% of farms were dependant. When diseases outbroke, 49.3% of farms called for veterinary hospital and the rest were handled by their own veterinarians, salesmen or professionals. Approximately 70% of farms were satisfied with the diagnosis made by the veterinarians. Frequency of disease outbreaks varied according to the age and type of birds. The livabilities of layers during the period of brooding, rearing ana adultwere 90.5, 98.9 and 75.2%, respectively while the livalibility of broilers until marketing was 92.2%. In layers, average culling age, was 533.3 day and hen housed eggs were 232.7. Average feed conversion rates of layers and broilers were 3.30 and 2.48, respectively. Those figures were considerably higher than anticipated but still far lower than those in developed countries.

• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.113-127
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• 2005

Cretaceous intrusive and extrusive rocks are widely distributed in the southwestern part of the Korean peninsula, possibly the result of intensive magmatism which occurred in response to subduction of the western proto-Pacific plate beneath the north-eastern part of the Eurasian plate. Geochemical and petrological study on the Cretaceous granitic rocks were carried out in order to constrain the petrogenesis of the granitic magma and to establish the paleotectonic environment of the area. Whole rock chemical data of the granitic rocks from the study area indicate that the all the rocks have characteristics of calc-alkaline series in the subalkaline field. The overall geochemical features show systematic variations in each granitic body, but the source materials of each granitic body are thought to have been different in their chemical composition. Higher values of $Fe_2O_3/FeO$ of the granitic rocks in the western area suggest that the granitoids had been solidified under highly oxidizing environment. The granitic bodies in the eastern area also show higher contents of Li, Ni, Co, Sr, Cr, Sc and lower Rb and Nb compared to the those of the western area. Chondrite normalized REE patterns show generally enriched LREE and strong negative Eu anomalies in the western wet while slight to flat Eu anomalies in the east-ern area. The REE and $(La/Lu)_{CN}$ of the granites are $60{\~}499ppm$ and $8.9{\~}66$ correspond to the range of the continental margin granite. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG and syn-collision granite. Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at continental margin during the subduction of proto-Pacific plate.

• Journal of the Korean earth science society
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• v.34 no.4
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• pp.313-328
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• 2013

Jurassic granitoids in the northeastern part of the Yeongnam Massif are possibly the result of intensive magmatic activities that occurred in response to subduction of the proto-Pacific plate beneath the northeast portion of the Eurasian plate. Geochemical studies on the granitic rocks are carried out in order to constrain the petrogenesis of the granitic magma and to establish the paleotectonic environment of the area. Whole rock chemical data of the Uljin granitoids in the northeastern part of the Yeongnam Massif indicate that all of the rocks have the characteristics of calcalkaline series in subalkaline field. The overall major element trends show systematic variations in each granitic body, but the source materials of each granitoids seem to have different chemical composition. The Uljin granitoids are different from other granitic rocks, which distributed vicinity of the study area, in the contents of $Al_2O_3$ and trace elements such as Cr, Co, Ni, Sr, Y and Nb. The Uljin granitoids have geochemical features similar to slab-derived adakites such as high $Al_2O_3$, Sr contents and high Sr/Y, La/Yb ratios, but they have low Y and Yb contents. The major ($SiO_2$, $Al_2O_3$, MgO) and trace element (Sr, Y, La, Yb) contents of the Uljin granitoids fall well within the adakitic field. The Uljin granitoids have similar geochemical characteristics, paleotectonic environments and intrusion ages to those of the Yatsuo plutonic rocks of Hida belt located on northwestern part of Japan. Chondrite normalized REE patterns show generally enriched LREEs ($(La/Yb)_{CN}=10.6-103.4$) and are slight negative to flat Eu anomalies. On the ANK vs. A/CNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type and volcanic arc granite (VAG). Interpretations of the chemical characteristics of the granitic rocks favor their emplacement in a compressional tectonic regime at the continental margin during the subduction of Izanagi plate in Jurassic period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.341-358
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• 1992

In order to estimate energy budgets of Palaemon macrodactylus, larvae of the shrimp were reared in the laboratory at constant conditions $(25^{\circ}C: 31-32\%o),$ and then juvenile to adult of the shrimp were reared at $15^{\circ}C\;and\;25^{\circ}C$ in the laboratory. Energy used by the reared shrimps were calculated from estimates of data on feeding, growth, molting, metabolism, nitrogen excretion, and energy content. Juveniles and adults reared in the laboratory, which fed on Artemia nauplii, had an average daily growth rates of 0.079 mm/day at $15^{\circ}C\;and\;of\;0.122mm/day\;at\;25^{\circ}C$. The average growth factor* of P. macrodactylus males and females ranged from $3.2\%$ for adult to $13.2\%$ for juveniles individuals, respectively. Intermolt periods were related to body size of the shrimp and to temperature. Average laboratory growth curves were calculated from data on growth factors and intermolt periods to body size of the shrimp at $15^{\circ}C\;and\;25^{\circ}C$. The calorie contents of the shrimp, their molts, eggs and larvae were determined by biochemical composition and oxygen bomb calorimetry. The average amount of energy used in growth for larvae and juvenile to adult were 4.94 cal and 4.55 cal per dry weight in milligram, respectively. The ammount of oxygen used in metabolism was calculated from size, temperature-specific respiration rate. To convert the ammount of oxygen used in respiration into the equivalent energy lost heat was estimated from the data on chemical composition for the larvae and adult, the values was 4.58 cal/ml $O_2$. The energy content per egg was 0.078 cal. The assimilation efficiency estimated by nitrogen content of food and egested faeces gave $61.5\%$ for the larvae. The efficiencies for juvenile to adult ranged between $79.4\%$ and $90.1\%$ The gross growth efficiencies $(K_1)$ and net growth efficiencies $(K_2)$ of P macrodactylus showed $18.33\%\;and 32.63\%$ for total larval stages, ranged from $21.30\%\;to\;31.04\%\;and\;from\;30.03\%\;to\;39.34\%$ for juvenile to adult, respectively.

• Research in Plant Disease
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• v.22 no.4
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• pp.227-235
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• 2016

Plant disease caused by root-knot nematode is a major problem in crop production. Using of chemical pesticides, one of the most efficient methods to control nematodes, have raised issues in toxicity to humans and animals and environmental pollution. In this study, to select actinomycete strains that have potential to serve as a microbial agent for control of nematodes, we investigated nematicidal activity of culture broth from 670 Streptomyces isolates. A culture filtrate of KRA15-528 isolate that was identified as S. flavogriseus on the basis of 16S rRNA sequence analysis, showed strong nematicidal activity against second stage of juveniles of Meloidogyne incognita and inhibited egg hatching; exposure to 10% of culture filtrate resulted in 71% juvenile mortality at 48 hours afters treatment and suppressed egg hatching by 54% at 9 days after treatment. When the KRA15-528 culture filtrate was partitioned with ethyl acetate and butanol, ethyl acetate layer exclusively showed strong activity; 91%, 53%, 30% of mortality at 1,000, 500, $250{\mu}g/ml$, respectively. Additionally, the culture filtrate suppressed gall formation on cucumber plant by M. incognita with no phytotoxicity. These results suggest that S. flavogriseus KRA15-528 has potential to serve as a microbial nematicide for the control of root-knot nematode disease.

• The Korean Journal of Malacology
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• v.24 no.2
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• pp.153-159
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• 2008

We investigated artificial mass seed production of a Chinese scallop, Patinopecten yessoensis, in 2004. The GSI(gonad somatic index) of the Chinese scallop, P yessoensis was 17.2 on mid-February, 20.2 on mid-March, while that of Korean scallop, P yessoensis was 6.9 on mid-February, 10.8 on mid-March. Matured 120 females and 350 males were selected for artificial mass production. They were exposed in air for 1 hr at over $20^{\circ}C$, and placed into a spawning tank(20 ton) containing sea water treated with UV radiation at $12^{\circ}C$. We gained a total of 228,000 thousand scallop embryos between March 10th and 15th, and reared larvae at the indoor tank during 25 days. When the mean shell length of larvae reached 250 ${\mu}m$ and they have eye-spots, the number of pre-settling larvae was 47,500 thousand. We gained 1,850 thousand attached scallop spats from two kinds of collectors. Attached spats were reared in indoor tank for different periods from 5 days to 60 days. They were divided into 5 groups according to the length of reared days. Each group of attached spats was moved to intermediate rearing sites at Yangyang fishing port in Gangreung-city for acclimation to ocean environments. The highest survival rate of attached spats was 13.0% shown at the group reared for 12 days, but the significant difference in their growth was not found between the groups. The shell length of artificial attached spats increased from 0.9 ${\mu}m$ on July 10th to 24.7 ${\mu}m$ on December 16th with the survival rate of 85.0% while that of natural attached spats increased from 0.6 ${\mu}m$ on July 10th to 23.9 ${\mu}m$ on December 16th with the survival rate of 85.7%.

• Economic and Environmental Geology
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• v.42 no.4
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• pp.289-300
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• 2009

The Geodo mine area, had been developed for Fe and Cu ores since 1963 and abandoned in recent decades, is located in the central part of the Taebaeksan mineralized district. This area comprises of the Jangsan, Myobong, Pungchon, Hwajeol, Dongjeom, and Dumugol Formations in ascending stratigraphic order. These Formations were intruded by the Cretaceous Eopyeong granitoids that appears to produce the Geodo skarn. Their compositions are relatively oxidized quartz monzodiorite to granodiorite (magnetite series, $Fe_2O_3/FeO=0.3{\sim}1.1$). Mineralizations related skarn deposit occur in the Myobong, Pungchon, and Hwajeol Formations. The proximal skarn is zoned from andraditic garnet ($Ad_{44-95}Gr_{1-53}$) predominant adjacent to the Eopyeong granitoids to diopsidic pyroxene ($Hd_{10-100}Di_{0-89}$) predominant away from the one. The differential proportion of garnet and pyroxene is generated by water/rock ratio and their source, such as magmatic and meteoric water. This is useful tool for assessment the overall oxidation state of the entire skarn system. Gold occurs in proximal red to brownish garnet skarn, and genetically associated with Bi- and Te-bearing minerals. Skarn deposit developed in the Geodo mine area is considered as oxidized Au skarn category, based on chemical composition of the Eopyeong granitoids, zonation of skarn, and gold occurrences. Garnet-rich skarn zone will be the main target for exploration of gold in the study area. However, it is needed to the detailed survey on vertical zonation of this area as well as lateral zonation. The result of this survey would provide an important basis for the exploration of the skarn Au deposit in the Geodo mine area.

• Journal of Life Science
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• v.21 no.11
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• pp.1541-1548
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• 2011

This study was carried out to evaluate the effects of the addition of different levels of CFP (Cordyceps with fly pupa) on growth performance in broiler chickens. 400 broiler chicks (Ross 308, 1 day old) were sorted randomly into 4 treatment groups and fed experimental diets for 35 days. The treatment groups were divided into a control group not fed with CFP (T1), and treatment groups fed with CFP 2.0% (T2), CFP 3.5% (T3), and CFP 5.0% (T4). Although the broilers' weight gain and feed efficiency were significantly higher (p<0.05) in the T3 group throughout the entirety of the test period, no statistically significant differences were noted among the T1 and T2, T4 groups. Triglyceride in the blood, total cholesterol, and LDL-C were significantly lower in the CFP treatment groups than in the control group (p<0.05). The blood lipid reduction rate ranged from 5.32 to 10.63% for triglycerides, from 9.23 to 12.62% for total cholesterol, and from 44.67 to 53.81% for LDL-C in the CFP treatment groups relative to the control group. The abdominal fat weight ratio was reduced significantly in the CFP treatment groups (p<0.05) compared with the control group, with a reduction rate range of 17.67-21.68%. Broiler carcass weight, carcass rate, and ratios of breast muscle, skin and thigh muscle weights to carcass weight were significantly higher in the T3 group, and statistically significant differences were noted among the T1 and T2, T4 groups (p<0.05). Enteropathogenic E.coli and Salmonella were lower in the CFP treatment groups than in the control group, whereas the beneficial bacteria Bifidobacteria were significantly higher in the CFP treatment groups than in the control group (p<0.05). These findings suggest that the Cordyceps with fly pupa can improve the carcass characteristics and body weight gain in broiler chickens.