• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.3
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• pp.177-186
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• 1970

The spawning of the abalone, Haliotis discus hannai, was induced In October 1969 by air ex-position for about 30 minutes. At temperatures of from 14.0 to $18.8^{\circ}C$, the youngest trochophore stage was reached within 22 hours after the egg was laid. The trochophore was transformed into the veliger stage within 34 hours after fertilization. For $7\~9$ days after oviposition the veliger floated in sea water and then settled to the bottom. The peristomal shell was secreted along the outer lip of the aperture of the larval shell, and the first respiratory pore appears at about 110 days after fertilization. The shell attained a length of 0.40 mm in 15 days, 1.39 mm in 49 days, 2.14 mm in 110 days, 5.20 mm in 170 days and 10.00 mm in 228 days respectively. Monthly growth rate of the shell length is expressed by the following equation :$L=0.9981\;e^{0.18659M}$ where L is shell length and M is time in month. The density of floating larvae in the culture tank was about 10 larvae per 100 co. The number of larvae attached to a polyethylene collector ($30\times20\;cm$) ranged from 10 to 600. Mortality of the settled larvae on the polyethylene collector was about $87.0\%$ during 170 days following settlement. The culture of Nauicula sp. was made with rough polyethylene collectors hung at three different depths, namely 5 cm, 45 cm and 85 cm. At each depth the highest cell concentration appeared after $15\~17$ days, and the numbers of cells are shown as follows: $$5\;cm\;34.3\times10^4\;Cells/cm^2$$ $$45\;cm\;27.2\times10^4\;Cells/cm^2$$ $$85\;cm\;26.3\times10^4\;Cells/cm^2$$ At temperatures of from 13.0 to $14.3^{\circ}C$, the distance travelled by the larvae (3.0 mm In shell length) averaged 11.36 mm for a Period of 30 days. Their locomation was relatively active between 6 p.m. and 9 p.m., and $52.2\%$ of them moved during this period. When the larvae (2.0 mm in shell length) were kept in water at $0\;to\;\~1.8^{\circ}C$, they moved 1.15cm between 4 p.m. and 8 p.m. and 0.10 cm between midnight and 8 a.m. The relationships between shell length and body weight of the abalone sampled from three different localities are shown as follows: Dolsan-do $W=0.2479\;L^{2.5721}$ Huksan-do $W=0.1001\;L^{3.1021}$ Pohang $W=0.9632\;L^{2.0611}$

• Korean Journal of Veterinary Research
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• v.15 no.1
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• pp.57-67
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• 1975

The poxvirus group is considered to be a typical cytoplasmic inclusion forming virus. Every poxvirus has been reported to produce only one kind of inclusion in the infected tissues. A vague concept that inclusions of poxviruses are eosinophilic or acidophilic has prevailed. Although many papers and theories about the nature of the inclusion have been presented, most of them are not quite convincing on the point of the relations with virus multiplication, and an analysis of papers published showed that there seem to be many discrepancies in the descriptions of the nature of the poxvirus inclusions. Comparative studies on host-virus interaction with cowpox, orf, swinepox and fowlpox viruses which selected from each Group (I-IV) of poxviruses were performed from the morphological and virological standpoints. At first, in cowpox virus-FL cell system, as a comparative model, cytoplasmic inclusion, nucleic acid metabolism by autoradiography and detection of viral antigen by immunofluorescence were studied and obtained the results as follows: 1. The focus-like cytopathic effect (CPE) at early stage developed to entire culture at terminal stage of infection, and also the developing status of CPE was correlated to viral doses for inoculation. Two kinds of cytoplasmic inclusions which named A and B type were easily observed by Giemsa, hematoxylin-eosin (H & E) and May-Greenwald Giemsa (MGG) stainings in the infected cells. The B type inclusions were formed at early stage of infection and the A type inclusions were produced subsequently the B type formation. The B type which common type inclusion in poxviruses was a small compact or aggregate at early stage and developed to a large diffuse body at terminal stage of infection. On the other hand, the A type inclusion which depend upon the kind of virus was appeared as round and discrete shape, and its size and number was increased gradually during the culture period. It was characteristic to form distinct halos around the both types of inclusions in acid fixed, H & E stained preparations of infected cultures. The B type inclusion was always positive in Feulgen reaction and showed as DNA containing body but the A type inclusion was not. 2. In the relationship between inclusion and DNA metabolism of infected cells by the qualitative autoradiography using 3H-thymidine, the appearance of silver grains was coincided with B type inclusion but not with A type inclusion. This showed that the DNA synthesis was proceeded in all B type inclusions except those in the terminal stage with a diffuse form. This suggested that the B type inclusions are only sites of DNA synthesis and this was proceeded after the cell infection independently. The activity of DNA synthesis of the inclusions was nearly the same as that of the nucleic of normal cells and non-inclusion bearing cells. and non-inclusion bearing cells. Regardless of the size of the degree of DNA synthesis of the B type inclusion, inclusion bearing cells all showed remarkable suppression of nuclear DNA synthesis. 3. By the direct fluorescent antibody technique viral antigen in infected cells was detected. The B type inclusions have been proved to contain a great deal of viral antigen, whereas the basic substance of A type inclusion did not show antigenicity except the round edge. It was suggested that the round edge fluorescence might be caused by the glare of cytoplasmic viral antigen which pushed out and concentrated by the A type inclusion development. 4. Hemorrhagic red pock formations on chorioallantoic membrane of embryonated chicken egg had proved the characteristic of used viral strain. 5. By the above studies on the nature of two types of inclusions and the role they play in virus multiplication, it was concluded that the B type inclusion must be the site of the synthesis of viral DNA and protein as well as the site of the virus.

• Journal of Life Science
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• v.22 no.7
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• pp.897-903
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• 2012

Food allergies have become a serious health concern in the past two decades, especially in developed countries. Foods associated with allergies include vegetables, some fruits, shellfish, wheat, egg, chicken, and nuts. To describe the specific fundamentals, etiological factors, and clinical manifestations, we analyzed the different physical frequency on spleen index in sensitized and regular exercise-trained mice. We also conducted a proliferation assay of lymphocytes to OVA, ROS, ASAS, and we determined the cytokine levels. Female BALB/c mice were bred in the animal laboratory of the P and D university under controlled conditions ($22{\pm}2^{\circ}C$, RH 45-55%, and a 12-hour photoperiod). The animals were 6 weeks old at the start of the study and were fed a standard commercial chow diet from 09:00 to 15:00 for the 8-week study period. All animals had access to distilled deionized water ad libitum. They were divided into four groups: a control group (S; control sensitized, n=25), a low-frequency training group (F2, n=25), a mid-frequency training group (F3, n=25), and a high-frequency training group (F5, n=25) following the treatment of exercise time per week. The results were as follows: The mice spleen index showed the highest grade in the F5 group compared with the other groups; this level showed in an exercise frequency-dependent manner. In the proliferation assay of OVA, the F5 group showed the highest grade compared with the other groups; this level was also showed in an exercise frequency-dependent manner. Peritoneal ROS and ASAS showed a statistically significant increase in the F5 group and decreased in the F2 group compared with the S group. However, there were no significant differences in the F3 group. The highest level of IL-4 was found in the F5 group compared with the other groups. However, the highest level of INF-${\gamma}$ was in the F2 group. The results suggest that FDEIA is positively correlated with the frequency of exercise due to the direct effect of physical exercise on peritoneal ROS and the cytokine profile. Further research is needed on the specific mechanism underlying the combined effects of exercise intensity and frequency on physical-induced allergy anaphylaxis.

• Korean Journal of Ichthyology
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• v.13 no.3
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• pp.181-189
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• 2001

Spawning behavior of the Takifugu pardarlis (Temminck et Schlegel) was observed on the Jook-do coast in Tongyong from March 1997 to June 1999. The spawning ground was locted in the intertidal zone between Tongyong and Koje-do. Its bottom was mainly gravels and stones, and its depth was 0.5~1.0 m. Spawning season was from the end of the March to the middle of May. During the spawning season, the mature fishes formed school a of 10~30 individuals, then moved to the spawning ground together. When a mature female spawned eggs, the attendant males fertilized them at the same time. The fertilized eggs obtained from the parent fishes caught at the spawning ground were adhesive, opaque and spherical, measuring 1.14~1.24 mm (mean 1.19 mm, n = 50) in diameter with numerous tiny oil globules. Hatching period was about 205 hours after fertilization at water temperature of $18.0{\pm}0.5^{\circ}C$. The newly hatched larvae were 2.92~3.10 mm (mean 3.01 mm, n = 20) in total length (TL), had a large yolk, and 11~13+14~15 = 25~28 myomeres. At 5 days, the larvae had attained 3.79~3.85 mm (mean 3.82 mm, n = 20) in TL and had transformed into the postlarval stage. At 15 days, the postlarvae had attained 7.78~7.90 mm (mean 7.84 mm, n = 20) in TL. At 21 days, had larvae attained 10.15~10.27 mm (mean 10.21 mm, n = 20) in TL and had reached the juvenile stage. All fins were formed with a complete set of fin rays having the following counts: dorsal fin rays 11~12; anal fin rays 9; pectoral fin rays 14~15; caudal fin rays 11~12.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.306-317
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• 2007

Reproductive cycle with the gonad developmental phases, first sexual maturity, spawning frequency, sex ratio of the dusky mud hopper, Periophthalmus modestus were investigated by histological observations. Monthly variations of the gonadosomatic index (GSI) began to increase in May and reached a maximum in June when the gonad was getting mature during the period of higher ground (water) temperature-long day length. Changes in the GSI showed a negative correlation to the HSI, but coincided with the fatness index. The reproductive cycle can be classified into five successive stages: in female, early growing stage (April to May), late growing stage (April to May), mature stage (May to June), ripe and spent stage (June to August), and recovery and resting stage (August to March); in males, growing stage (April to May), mature stage (May to June), ripe and spent stage (June to August), and recovery and resting stage (August to March); According to the frequency distributions of egg diameters during the breeding season, Periophthalmus modestus is presumed to be a summer breeder, asynchronous group and polycyclic species to spawn 2 times or more during the spawning season. Total eggs and mature eggs in absolute fecundity and relative fecundity (per cm) increased with the increase of body length. Total eggs and mature eggs in absolute fecundity and relative fecundity (per g) did not increase with the increase of body weight. Percentages of first sexual maturity of females and males ranging from 5.1 to 5.5 cm in body length are over 50%, and 100% for fish over 7.1 cm in body length. The sex ratios of females to males over 5.1 cm in body length were not significantly different from a 1 : 1 sex ratio.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.420-432
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• 2011

Population dynamics of greenhouse whitefly, Trialeurodes vaporariorum (Westwood), were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator (pre-programed module based simulation program developed by CSIRO, Australia). The DYMEX model simulator consisted of temperature dependent development and oviposition modules. The normalized cumulative frequency distributions of the developmental period for immature and oviposition frequency rate and survival rate for adult of greenhouse whitefly were fitted to two-parameter Weibull function. Leaf temperature on reversed side of cherry tomato leafs (Lycopersicon esculentum cv. Koko) was monitored according to three tomato plant positions (top, > 1.6 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at same three positions using a Hobo self-contained temperature logger. The leaf temperatures from three plant positions were described as a function of the air temperatures with 3-parameter exponential and sigmoidal models. Data sets of observed air temperature and predicted leaf temperatures were prepared, and incorporated into the DYMEX simulator to compare the effects of air and leaf temperature on population dynamics of greenhouse whitefly. The number of greenhouse whitefly immatures was counted by visual inspection in three tomato plant positions to verify the performance of DYMEX simulation in cherry tomato greenhouse where air and leaf temperatures were monitored. The egg stage of greenhouse whitefly was not counted due to its small size. A significant positive correlation between the observed and the predicted numbers of immature and adults were found when the leaf temperatures were incorporated into DYMEX simulation, but no significant correlation was observed with the air temperatures. This study demonstrated that the population dynamics of greenhouse whitefly was affected greatly by the leaf temperatures, rather than air temperatures, and thus the leaf surface temperature should be considered for management of greenhouse whitefly in cherry tomato grown in greenhouses.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.117-123
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• 2009

This work was conducted to evaluate the effects of induced-molting methods on visceral organs and blood stress indicators in laying hens. One hundred fifty of 63-wk-old White Leghorn hens, with over 85% of egg production and $1.7\;{\pm}0.4\;kg$ of average weight, were used in this study. Treatments were control (non-molt treatment), feeding molt treatment (FM), and starving molt treatment (SM). There were 5 replicates of 10 hens for each treatment. All treatment groups were fed basal diet (15% CP and 2,700 kal/kg of ME) for two weeks as adaptation period. Heart weights were 8.2, 7.9 and 7.5 g in control, FM and SM, respectively. Liver and oviduct weights were decreased in both molting treatments compared with control (P<0.05). Corticosterone (CS) concentrations were 4.48, 4.47 and $4.66\;{\mu}g/mL$ in control, FM and SM at 61 weeks, respectively, but increased to 7.32, 7.11 and $7.71\;{\mu}g/mL$ at 62 weeks, respectively (P<0.05). Heterophil to lymphocyte ratios were 0.27~0.29 in all groups at 61 weeks, but increased to 0.97~1.03 in SM at 62 weeks. Both CS concentrations and H:L ratios in SM were greater compared with those for the other groups. These results suggest that hens in feeding molting program in hens are less stressed than those in starving molting one.

• Korean Journal of Poultry Science
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• v.8 no.1
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• pp.1-5
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• 1981

In trying to predict the effect of genetics on the broiler in the year 2000, this is a relatively short period of time as far as broiler genetics in concerned. Modern broiler genetics started around 1945 and tremendous gains when made in past 35 years. Futher improvements on broiler will depend on the evolution and revolution: 1. Evolution: (1) Growth rate has been made 4-5% per year. (2) Feed conversion has improved approximately 1% per year. (3) Abdominal fat is becoming a major complaint in broiler. (4) Because of the changing life-style, broiler meat sales in the future will be more and more in cut-up form. (5) Breeding for stress resistance and selection for docile temperament can be important in order to funker improve fled efficiency. (6) In female parent stock, reproduction characteristics are in many can negatively correlated with the desired broiler traits. (7) Egg production and hatchability in moot commercial parent nod m at a fairly high level. (8) In male parent stock, the heavier and mon super-meat-type male lines are desired to Product better broilers. 2. Revolution: Trying to forecast revolutionary change in broiler genetics is highly speculative, as sudden change are aften unpredictable. (1) Species hybridization, such as a turkey-chicken cross (2) Biochemical tools, such as blood typing. (3) Mutation breeding by radiation or chemical mutagentia. (4) Broiler breeding would be to change the phenotypic appearance by single gene, such as naked, wingless. (5) Changes in production techniques. such as growing in cage or growing in filtered air positive pressure houses.

• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.286-291
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• 2003

We investigated the effects of molting-hormone insecticide tebufenozide on D7 (the day of hatching from egg) larvae of the midge Chironomus riparius in growth developments. D7 instar larvae were exposed test concentrations were chosen control, 10${\mu}g \;L^{-1}$, 30${\mu}g \;L^{-1}$, 60${\mu}g \;L^{-1}$ and 100${\mu}g \;L^{-1}$ of tebufenozide. In general, dead larvae showed 16% on the next day after insecticide treatments (D12), and observed 44% from D12 to D16 in this exposed days. Dead larvae of C. riparius was abruptly increased on D12 and also continuously increased along the days in 10${\mu}g \;L^{-1}$ treatments. The converged day was from D12 to D16 at move 30${\mu}g \;L^{-1}$ treatments in this study. Therefore, dead larvae obviously increased along these concentrations of tebufenozide. In control condition,78% of the test individuals have grown the pupae. But the larvae have developed the pupa stage from 5% to 17% of the test organism in 10${\mu}g \;L^{-1}$ and 30${\mu}g \;L^{-1}$ treatments. And 75% of the test individuals was arrived the adult through the molting process in control condition. While the other condition was rarely observed the adult. Usually, the emerged period of the test individuals was gathered the D26-D29 in control. The dead pupa showed from D19 to D20 in 30${\mu}g \;L^{-1}$ treatments, D32 in control and D33 in 10${\mu}g \;L^{-1}$ treatments. The observed periods of dead pupa were D32-D34 in control and D33-D37 in 10${\mu}g \;L^{-1}$ treatments. Consequently, due to molting hormone disruption, development of midge was postponed relatively low concentration such as 10 treatments of tebufenozide.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.217-226
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• 2014

Root-knot symptoms were found on a commercial tomato cultivar carrying Mi, a resistance gene to root-knot nematodes including Meloidogyne incognita, M. arenaria, and M. javanica in 2012 at Buyeo, Chungnam Province in Korea. The isolate was identified as M. incognita based on molecular analyses using two species-specific primer sets. Pathogenicity of the isolate on one susceptible and three resistant tomato cultivars to the root-knot nematodes was tested. The nematode isolate showed strong pathogenicity on all the tested cultivars at all tested incubation temperatures. In addition, resistance degree of 33 commercial tomato cultivars, 8 susceptible and 25 resistant cultivars to root-knot nematodes, was also tested. Plants were determined as resistant when they suppressed the nematode reproduction. All the cultivars demonstrated strong susceptibility to the nematode regardless of resistance of the tomato cultivars. To our knowledge, this is the first report on the occurrence of Mi infecting M. incognita isolate in Korea. On the other hand, to construct an efficient screening method for selecting resistant breeding source to the nematode isolate, root-knot development of M. incognita on four tomato cultivars according to several conditions such as inoculum concentration, plant growth stage, and incubation period after transplant was investigated. Reproduction of the nematode on all the tested cultivars according to inoculum concentration increased in a dose-dependent manner. Except for inoculum concentration, there was no significant difference in reproduction level of the cultivars according to the other tested conditions. On the basis of the results, we suggest an efficient screening method for new resistant tomato to the nematode isolate.