• Journal of Sericultural and Entomological Science
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• v.51 no.1
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• pp.73-77
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• 2013

Silkworm transgenesis scientists have done some genetic modification work on multivoltine silkworms, but that type of silkworms is less commercial feasible. They are easy to manipulate, because they breed all year round. But the commercial silkworm variety must undergo hydrochloric acid treatment at a high temperature to be artificially hatched. Hydrochloric acid penetrates through the holes in the silkworm eggs, fatally damaging their reproduction. So it had been thought that altering the properties of the commercial silkworm variety would be very difficult. So we have tried to make from diapause to non-diapause eggs using diapauses varieties, 'Backokjam' and 'Jam 124'. At present, our group has establishing the conditions for non-diapause eggs. Oviposited eggs after 40 ~ 60 hours were incubated for 24 hours at $15{\sim}20^{\circ}C$ with dark condition. Non-diapause eggs were completely induced. The hatching rate, molting rate and pupation rate of non-diapause 'Jam 124' and 'Backokjam' eggs showed no differences compared to diapause eggs. When transgenic silkworm using the non-diapause eggs, the hatching rate showed that non-diapause eggs induced from diapause were 40 ~ 70%, diapause eggs treated with artificial incubation were 10 ~ 30%, and polyvoltine strains, HM eggs were 30 ~ 50%. Therefore, we suggest that modification techniques of the commercial silkworm eggs adequate for silkworm transgenesis can be used to develop transgenic silkworms more easily.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.559-568
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• 2012

White (Lohmann LSL) and Brown (ATAK-S) laying hens, were reared under organic and conventional cage rearing systems, and the effects of the rearing system on performance parameters, egg production, egg characteristics, and immune response were investigated. For this purpose, a total of 832 laying hens of two commercial hybrids, i.e., 416 white (Lohmann LSL) and 416 Brown (ATAK-S) layers, were used. The experiment lasted between 23 and 70 wk of age. In this study, the white layers yielded more eggs as compared to the brown layers in both organic and conventional production systems. Egg weight exhibited a similar pattern to that of laying performance. However, the total hen-housed egg number for the white birds in the organic system was fewer than that of white birds in the conventional cage facility; conversely, a contradictory tendency was observed for the brown birds. Livability of the white layers in the organic system was remarkably lower (14%) than that of the brown line, whereas the white line survived better (3.42%) than their brown counterparts in conventional cages. The feed conversion ratio of the white hens was markedly inferior in the organic system as compared to that of the white hens in the conventional system, whereas relatively lower deterioration was reported in brown layers when reared in an organic system. The organic production system increased egg albumen height and the Haugh unit in eggs of the brown layers. The yolk color score of organic eggs was lower than that of conventional eggs for both brown and white hens. The egg yolk ratio of eggs from white layers was found to be higher in organic eggs as compared to those obtained in the conventional system. All organic eggs had heavier shells than those produced in the conventional system. Eggs from brown layers had more protein content than eggs from white layers. Neither housing systems nor genotype influenced egg yolk cholesterol concentration. When compared to conventional eggs, n-3 fatty acid content was lower in organic eggs, and the n-6:n-3 ratio was higher in organic eggs. In conclusion, two hen genotypes showed different responses in terms of performance and egg quality to two different rearing systems. A commercial white strain produced more eggs with higher egg quality as compared to a native brown strain. The brown strain was found to have adapted well to organic production conditions when survival and total egg number was taken into consideration.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.2
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• pp.96-104
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• 2008

An egg grading machine is composed of many mechanisms of which functions are to carry eggs to the bucket in that sensors are located to categorize eggs by their weight, to transfer eggs from the basket of packer holder to the mold tray, to feed the mold tray dispenser after egg chairs are filled with eggs. This paper deals with the analysis and new design of packer holder mechanism of which function is transfer eggs vertically from the bucket conveyor to the mold tray dispenser. Egg is fragile to impact so in designing packer holder mechanism it is necessary to estimate moving speed, acceleration and impact when eggs are touched by any links of mechanism and mold tray dispenser. A new packer holder mechanism is proposed in this paper, which use quick return mechanism composed of 6 links with pin and contact joints.

• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.148-152
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• 1985

When goat spermatozoa were preincubated for 4-6 h and 6 h in the uteri isolated from hamster and rat, and for 6 h in the hamster uterus in situ, they developed the ability to penetrate zona-free hamster eggs in vitro. Zona-free hamster eggs were not penetrated after insemination with goat spermatozoa preincubated in the isolated hamster uterus 4 h before and 2 h after expected time of ovulation, respectively. Zona-free hamster eggs were not penetrated after insemination with goat spermatozoa preincubated for 4 h in the isolated hamster uterus, but 10 and 18% of eggs were penetrated by spermatozoa preincubated for 5 and 6 h in the isolated uterus.

• International Journal of Industrial Entomology and Biomaterials
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• v.15 no.2
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• pp.165-169
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• 2007

A differential specific pattern of variation in the metabolism of protein and cholesterol was noticed in non -diapause and diapause eggs due to the significant differences in embryonic development. The rate of metabolism was different due to specific demands of such metabolites during active embryogenesis and maintenance of diapause respectively. In general, the metabolic rate was found to be accelerated in non- diapause eggs just after egg deposition, while it was very slow in diapause eggs. When the diapause eggs were treated with hydrochloric acid within 16-20 hrs, the rate of turnover was found to very similar to non- diapause eggs, though the base level of protein and cholesterol was recorded to be different.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.68-71
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• 1998

The egg structure and shape of the skin parasite, Entobdella hippoglossi from the Atlantic halibut, Hippoglossus hippoglossus was examined using scanning electronic microscope. The newly produced eggs of E. hippoglossi were yellowish in color and tetrahedral in shape. The eggs were entwined together in a complicated chain-like fashion by a long filament. The appendage showed the presence of buoy-like structures. The buoy-like structures on the appendage of the eggs of E. hippoglossi in the present study were totally different from other sticky droplets. It is suggested that these structures are not sticky droplets but buoys for floating eggs which have entwined together on the bottom of the sea. It seems that these buoy-like structures may be needed for preventing the eggs from being covered by mud or particles and thus maintaining the eggs in an oxygenated environment.

• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.126-134
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• 2000

We investigated the distribution of the marine cladoceran resting eggs in the intertidal sediments of Gomso Bay, Korea and compared the data with those in the subtidal sediments. The abundance of the eggs in the top 6cm of the sediments was higher than that in the other depths. The abundances of the eggs in seaward intertidal sediments below mean sea level (MSL) were higher than those in the sediments over MSL, but were not significantly different from those in the subtidal sediments. The distribution of the resting eggs of cladocerans in the intertidal sediments was affected by the grain-size and moisture content of sediments. The results of the present study suggest that the intertidal sediments as well as the subtidal sediments are a potential egg bank which plays important roles in population dynamics of zooplankton in coastal waters, in particular, recruitment of eggs into plankton.

• Journal of the korean society of oceanography
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• v.37 no.3
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• pp.108-115
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• 2002

To Investigate the distribution of resting eggs at the intertidal zone, Gomso Bay, samples were taken from the top of the sediments to 10 cm depth at four sites using a cylindrical corer in February, 1997. Additional samples were also taken from one station at subtidal zone to compare the distributions between the inter- and subtidal zones. The resting eggs of few copepods, Acartia pacifica, Centropages abdominalis, Calanopia thompsoni, and Tortanus forcipatus were studied. Mostly, the abundance of the resting eggs in the lower intertidal zone was greater than that in the upper intertidal zone, but was not significantly different from that in the subtidal zone. The abundance of the resting eggs in the intertidal sediments was related with the grain-size and moisture content of sediments. Intertidal sediments are potential egg banks like subtidal sediments.

• Journal of the korean veterinary medical association
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• v.48 no.9
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• pp.540-543
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• 2012

Livestock excretes are frequently used in organic farming to produce vegetables and crops. However, zoonotic parasite eggs can be contaminated into such products and people can be infected with parasites of animal origin. Sporadic zoonotic infections with Ascaris suum have been reported even in developed countries, such as North America, Denmark, and the United Kingdom. Ascaris eggs are resistant to most adverse environmental conditions, and pigs and humans become infected by ingestion of fecally excreted eggs through contaminated food, water, or soil. This article discusses the resistant nature of ascarid eggs against harsh environment, and conditions of kimchi to be safe from consuming viable A. suum eggs.

• Journal of Environmental Health Sciences
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• v.3 no.1
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• pp.17-21
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• 1976

Korea Parasite Eradication Association alleged in its seasonal report spring/1975 that 36.8 percent of primary, middle and high school students in Seoul area are infected with parasites. For the purpose of a comparative study between the high rate of parasite infection among Korean students and that of parasite eggs attached to vegetables which perform intermediary role in carrying the eggs to human body, such vegetables as lettuce, Korean cabbage, young radish, green onion, cabbage which are on sale at several markets in Seoul city are sampled at random for study. The infection rate of parasitic eggs and larvae on vegetables is studied twice while the detaching mean while removing rate of eggs and larvae in proportion to the number of washing them is studied three times. Every 300 grams of vegetables is taken at random for examination and every one of them is washed with a hard brush and then the kinds of parasite eggs and the ratio of eggs attached to them are studied.