• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.2
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• pp.1948-1959
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• 1970

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.33.3-34
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• 2021

In LCDM universe, large, massive structures, like galaxy clusters, grow through the successive accretion/mergers of smaller structures. Therefore, at high redshift, unlike local, it is expected that there would be plenty of galaxy clusters which are still growing. Here, we report the discovery of a high-redshift (z~1) galaxy cluster which is in its active formation stage. This cluster is well connected to the large scale overdense environment and contains high fraction of star-forming galaxies, providing a good example supporting our previously suggested 'Web-feeding model'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.310-316
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• 1987

A field experiment was conducted to find out the effects of liming(soil pH) and sources of N on growing characters and yield of burley tobacco. Treatments consisted of liming(nonliming, liming to soil pH5.5 and 6.5) as the main plot and N sources(compound fertilizer of containing 3.9% NH$_4$-N and 6.1% NH$_2$-N, NaNO$_3$,(NH$_2$)$_2$CO and (NH$_4$)$_2$SO$_4$as the sub-plot. The growth of vegetative growing stage of limed plots were delayed(to compare the nonlimed plot) by influence of alkali. When the source on N was NaNO$_3$ the growth of vegetative growing stage was unfavorable and the yellowing of lower leaves of maturing stage was rapid. The yield and value of cured leaf was increased by increasing the rate of Ca(OH)$_2$, but there was no significant differences among the source of N. The yield response to liming was greater when the source of N was (NH$_4$)$_2$SO$_4$ than that of any other plots.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.587-591
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• 2004

Blood samples from 622 pigs of 44 farms which were sero-positive to Mycoplasma hyopneumoniae (M. hyo) by ELISA method were collected from May 2003 to July 2004. And they were divided into 2 categories : M. hyo-vaccinated group (7 swine farms) and M. hyo-non-vaccinated group (37 swine farms). Then, each swine farm was analysed by sero-positive percentage per weeks of age. It was observed that the sero-positive percentage to M. hyo is directly proportional to weeks of age in the 44 swine farms that were selected. This meant that there has been a chronic infection of M. hyo in Korean swine herds and control of M. hyo infection did not have worked efficiently. In 7 M. hyo-vaccinated swine farms, there were no reliable patterns between sero-positive percentage to M. hyo and weeks of age. Although the swine farms have been used M. hyo vaccine, they had only little sero-positive percentage that was less than 50% at 6 to 11 weeks of age. This means a present vaccination program does not induce sufficiently a seroconversion expected. In 37 M. hyo-non-vaccinated swine farms, it was observed that sero-positive percentage was higher at above 15 weeks of age. This result showed that infection of M. hyo occurred commonly at between 7 and 12 weeks of age, at which pigs moved to the growing house. Because a risk of natural infection is severe at growing stage as well as nursery stage, it suggested that M. hyo vaccination at several weeks prior to the growing stage will give efficient effect to control the enzootic pneumonia.

• Journal of Aquaculture
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• v.17 no.1
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• pp.30-38
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• 2004

To estimate the spawning period the annual change of gonadosomatic index (GSI) were examined from January 2000 to December 2001. Fecundity, spawning frequency and egg diameter were measured by ocular observation. Germ cell differentiation during gametogenesis, the reproductive cycle and the first sexual maturity of greenling Hexagrammos otakii were observed under light microscopy from January to December, 2000. GSI began to increase in August and reached the maximum in November when ovary was getting mature. The reproductive cycle of H. otakii can be divided into five successive stages in females: early growing stage (July), late growing stage (July to August), mature stage (September to October), ripe and spent stage (September to December), and recovery and resting stage (December to June). Males showed four successive stages : growing (June to August), mature (August to October), ripe and spent (September to December), and recovery and resting stage (December to May). According to the frequency distributions of egg diameter in spawning season, H. otakii could be one of polycyclic species spawning 2 times or more during one spawning season. Number of total eggs and mature eggs in the absolute fecundity were related to the standard length and body weight, respectively. Number of total eggs and mature eggs in relative fecundity were also proportional to the standard length, but rather these numbers decreased with body weight. Percentages of first sexual maturity of females and males in greenling were over 50% from 19.1 to 21.1cm in length, and 100% for fish over 25.1cm in length. Therefore, both sexes are ready to reproduce after one year old.

• Journal of Ecology and Environment
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• v.33 no.2
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• pp.149-155
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• 2010

This study was conducted to investigate the feeding efficiency of the cattle egret (Bubulcus ibis) and the intermediate egret (Ardea intermedia) in relation to the stage of rice culture during two breeding seasons, 2006 and 2007, in Asan city, Chungcheongnam-do, South Korea. Cattle egrets caught mainly small invertebrate prey (insects and spiders, 98.4%) during all stages of rice cultivation, and had a higher prey capture rate in the plowing stage (14.98 prey/min) than in other stages (2.82-3.51 prey/min). Therefore, the biomass intake rate of cattle egrets was highest in the plowing stage. The intermediate egret captured both loaches (43.4%) and small invertebrates (50.6%). The prey capture rates of intermediate egrets increased gradually from the flooding stage (0.38 prey/min) to the planting stage (1.09 prey/min), and decreased in the growing stage (1.04 prey/min). However, intermediate egrets had the highest biomass intake rates in the plowing stage because more loaches were caught in the plowing stage (0.54 loaches/min) than other stages (0.23-0.36 loaches/min). Consequently, both intermediate egrets and cattle egrets had high energy intakes in the plowing stage and rice fields provided an important feeding habitat for both species.

• The Korean Journal of Mycology
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• v.37 no.2
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• pp.150-154
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• 2009

The diversity of microflora according to growth stage of Pleurotus ostreatus and the correlation between microbe and medium fermentation were investigated. In farmhouse I, the aerobic bacteria and fungi as longer of growing period were increased. And, thermophilic bacteria and fluorescent Pseudomonas sp. showed high density at the early stage of spawn inoculation. The thermophilic actinomycetes were distributed evenly during all the growing period, but mesophilic actinomycetes were not observed. In farmhouse II, thermophilic actinomycetes were not observed in fermented medium and density of fungi were suddenly increased at 60 days after spawn inoculation. And also, mushrooms can hardly be harvested due to Penicillium spp. After medium fermentation, density of aerobic bacteria, thermophilic bacteria, and fluorescent Pseudomonas sp. was higher at farmhouse I than those of farmhouse II. In farmhouse I, Bacillus sp. and Pseudomonas sp. dominated at early stage of mushroom growth but as time goes by, density of Bacillus sp. was higher than the others. And also, the kind of microbe showed a few at early stage of mushroom growth but increased as time goes by. In farmhouse II, Bacillus sp. was dominated at early stage of mushroom growth. And the growth of Bacillus sp. and Pseudomonas sp. showed intersect aspect each other in the farmhouse I but Bacillus sp. dominated during all growth periods in the farmhouse II.

• Development and Reproduction
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• v.12 no.2
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• pp.169-181
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• 2008

Reproductive ecology of the silver pomfret, Pampus argenteus were investigated by histological observations and morphometric data. Samples were collected by the stow net at the coastal area of Jaun-Do, Muan-gun, Korea, from January to December, 2006. P. argenteus is dioecious, the ovary is composed of many ovarian lobules, showing a pair of saccular structure, and the testis is composed of many seminiferous lobules, showing a pair of lobular structure. From February (growing stage) to September (after spawning), monthly changes in the gonadosomatic index, hepatosomatic index, and condition factor in females and males showed similar patterns with the gonad developmental phases. Judging from the results of their indice, it is assumed that spawning in females and males occur from May to July. The reproductive cycle can be classified into five successive stages in females: early growing stage (February to March), late growing stage (March to April), mature stage (March to July), ripe and spent stage (May to July), and recovery and resting stage (July to February); in males, the cycle can be divided into four successive stages: growing stage (February to April), mature stage (March to June), ripe and spent stage (May to July), and recovery and resting stage (July to February). According to the frequency distributions of egg diameters in the breeding season, P. argenteus is presumed to be spring-summer spawning species and polycyclic species to spawn 2 times or more during one spawning season. Number of total eggs in absolute fecundity were proportional to body length and body weight, respectively. Number of total eggs in absolute fecundity per body weight were also proportional to the body length, but if the increase of body weight considerably increased, rather total eggs in relative fecundity decreased with the increase of body weight. Percentage of first sexual maturity of P. argenteus were over 50% in females and males of 12.1 to 15.0 cm in body length, and 100% for fishes over 18.1 cm in length. Therefore, both sexes were regarded to be sexually mature at one year of age.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.74-81
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• 2008

To elucidate the exposure of pesticide in agricultural environment and to investigate distribution of pesticide in paddy fields. This experiment was carried out to clarify pesticide distribution in paddy fields applied with different formulations and growing stages. Initial dissipation rate of applied butachlor EW and oxadiazon EC before rice planting were more than 90% within 3 days in paddy fields. The distribution of a.i. in the pesticide formulations tested depended upon the elapsed time at each growing stage of rice plant after application. Most of pesticides applied within 15 days after transplanting of rice seedlings, more than 95%, were located in the surface water and soil regardless of pesticides; butachlor, thiobencarb and molinate GR. The distribution of iprobenfos GR, tricyclazole WP and phenthoate EC, after application 2 hours in middle growing stage (46 days after rice planting) were shown as 16.1, 48.9 and 38.9% in surface water, 83.6, 15.4 and 10.7% in soil, and 0.3, 35.7 and 50.4% in rice plants of paddy fields, respectively. Also tricyclazole WP and phenthoate EC, after application 2 hours in the late rice growing stage (90 days after rice planting) were distributed to 7.8 and 9.8% in surface water, and 21.7 and 5.1% in soil, and 70.5 and 85.1% in rice plants of paddy fields, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1383-1388
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• 2008

Because of high growth rate and large deposition of fat in the abdomen, the chicken has been used as a model organism for understanding lipid metabolism, fattening and growing. In this study, differentially expression of proteins in chicken liver, one of the important organs for lipid metabolism, has been investigated at four different growing stages. After separation of proteins using two-dimensional electrophoresis (2-DE), more than 700 protein spots were detected. Among them, 13 growing stage specific proteins in chicken liver were selected and further investigated by matrix-assisted laser adsorptions ionization-time of flight mass spectrometry (MALDI-TOF MS). Of these, 12 proteins were matched to existing proteins based on a database search. The identified fat-related proteins in this study were fatty acid synthase (FASN) and malic enzyme (ME1). These proteins were more highly expressed at week 32 than at other weeks. In order to confirm the differential expression, one of the proteins, FASN, was confirmed by western blotting. The identified proteins will give valuable information on biochemical roles in chicken liver, especially for lipid metabolism.