• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.209-216
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• 1974

Life history and control methods of Aphanostigma iakusuiense Kishida were studied during April to November, 1974, in the Naju pear orchard area, Cholla Namdo. The results are summarized as follows: 1. More than $60\%$ of wintering eggs were found at the height of 1.5 to 2.0m from the soil surface, with approximately $10\%$ at 0.5 to 1.5m and 1.5 to 2.5m respectively. 2. There was little difference in the size of egg masses and hatching ratio $(12.7-13.7\%)$ between the varieties of host trees, Mansamkil and Kooksoo. 3. Hatching was not observed until April 6, but hatches of $12.8\%$ on April 13 and $90.6\%$ on May 4 were found. 4. During the hatching season in early spring, 8 chemicals were applied to test effectiveness of control. C8514, Metasystox, Acar 338, and Parathion were more effective than either Sevin or Malix for control of this insect. 5. Highest populations of pear phylloxera ocurred from August 20 to September 20 at which time levels of eggs and larvae were simillar in abundance. 6. In tests for control of this insect after in paper bags, DDVP, Loxon, C8514, Sevin, and Binapacryl were more effective than either EPN or Otran. 7. Predacious mite, Protolaelape pygmaeus Miller, and several species of lady beetles (Coccinellidae) preying on this insect as natural enemies were collected. The predation ratio of mites varied according to region: that is 0.77 to $18.6\%$ in Bia Orchard; $7.88-48.7\%$ in Noan Orchard and almost none in Youngsanoo Orchard. 8. The varietal difference in fruit damage by this insect was in the order of Choseng Chuck, Kooksoo, followed by Sin Ko, Mansamkil, Keumchon Choo, and Changsimrang.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.55-63
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• 2002

This experiment was to know properties of Sericin Jam that development, growth of silkgland, content of sericin and composition of amino acid in hemolymph. The characters of Sericin Jam can he seen form this experiment. Hatching ratio was 85% in Sericin Jam and 95% in Jam 120. Especially hatching period of Sericin Jam was longer than Jam 120 and also hatching of Sericin Jam was ununiform. The larval duration of Sericin Jam was 20 days and 23 hours, and Jaw 120 was 21 days and 22 hours. In Sericin Jam, middle silkgland contain a great p arts in silkgalod and posterior silkgand is short and no curves. The period of mounting to emergence was 12 days in Sericin Jam. The period of pupa was 7day. It is property of Sericin Jam that the period is short. Cocoon was very thin and light in Sericin Jam. Weight of cocoon shell of Sericin Jam is 2.7cg. The sericin protein quantity was 100% in cocoon shell of Sericin Jam, about 28% in cocoon shell of Jam 120, however the sericin ratio per Sericin Jam cocoon was 34.6% compare to cocoon shell of Jaw 120 in sericin protein quantity. The amino acids in hemolymph of Sericin Jaw was much hidtidine, lysine, glut amic acid. And the amount of almost amino acids were increased depends upon development at t he 5th instar.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.95-99
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• 2003

A total of 112 male and 1208 female Ross broiler breeders (30-wk-old) were used in this study to investigate whether a male to female (M/F) ratio of broiler breeder chickens may influence fertility and hatchability of hatching eggs. There were three treatments, each consisting of four pens with a size of 3.2 m ${\times}$ 6.4 m. Each pen housed approx. 100 females and 10 males to give the M/F ratio as follows: T1, 1/9; T2, 1/11; and T3, 1/13, respectively. The fertility of broiler breeder eggs ranged between 93 to 94％ at 30 wk of age. At 35 wk of age, breeder eggs from T3 tended to be less fertile (P>0.05) than those from T1 and T2. The low fertility observed in T3 at 35 wk of age further reduced to reach a statistical significance at 46 wk of age (P<0.05) when compared to those of T1 and T2. Hatchability of breeder eggs among treatments tended to follow a similar trend as shown in fertility, keeping hatchability of breeder eggs from T3 low when compared to the groups of T1 and T2. Our results indicated that the M/F ratio influenced fertility and consequently hatchability of breeder eggs. Furthermore, our study suggests that either 1/9 or 1/11 M/F ratio, but not 1/13 M/F ratio, seems suitable to sustain reproductive performance of broiler breeders throughout the laying periods.

• Resources Recycling
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• v.7 no.3
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• pp.52-57
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• 1998

The objective of this study was to investigate the effect of cow manure as additive material on the ripening of sewage s sludge for vermistabiJization. The changes of the waste properties by ripening for 50days were observed as a function of the v various mixture ratios of sewage sludge ‘and cow manure. The pH values of the mixture wastes decreased from 7.5-7.67 to 6_ 9~7.2 by the ripening for 50days, and the mixture ratio made dIfferent pH values. The initial value of oxidation-reduction p potential (Eh) of the mixture waste was a negative (-) value indicating an unfavorable condition for earthworm after, but the v values of Eh increased with the opening time. The Increase rate at Eh value was prop$\alpha$rtional to the mixture ratio of cow m manure. The value of alkalinity was also changed into the favorable range for earthworm after 50days except for non-use of 1 the cow manure When the mixture ratio of the cow manure increased from 10% to 30%, the growth of earthworms increased h from 63.7% to 88.3 % tor the survival rate, 265% to 321% for the liveweight increasing rate and 66.7_7% to 91% for hatching f rate of the cocoons. It can be concluded that the proper content of tbe cow manure in the sewage sludge to ensure effective v vermistabilization was over 20%, when the mixture was ripened during 50 days. The quantity of ingestion and 며ectian at 20%-30% was found to be O.15--i.L18g sludge and 0 1l--O.14g solid per capacity earthworm per day, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.19-24
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• 2007

Covariance components and genetic parameters of weekly live body weight from hatching to six weeks of age and age of sexual maturation were estimated in a laying type Japanese quail line. The univariate and bivariate animal model analysis included hatching group and sex as fixed effects. Each trait was analysed with animal as random effect to fit the additive direct effect. Additional random effects incorporated in the models were changed according to the trait examined. The best model for a trait was chosen based on a likelihood ratio test, comparing the models with and without maternal additive genetic and maternal permanent environmental effects. Heritability estimates of live-weight at hatch and one to six weeks of age with their standard errors were 0.22${\pm}$0.088, 0.39${\pm}$0.099, 0.31${\pm}$0.086, 0.38${\pm}$0.056, 0.46${\pm}$0.055, 0.50${\pm}$0.059, and 0.56${\pm}$0.062, respectively. Direct heritability value of age of sexual maturation was moderate (0.24${\pm}$0.055). The variances due to permanent environmental effect of dam after one week of age and maternal genetic effect after two weeks of age were not important sources of variation. The correlations between direct and maternal genetic effects were negative and ranged from high to moderate values (-0.21 to -0.83). Among the weekly live weights, genetic correlations were generally high between not only successive but also early and late weightings. It suggests that selection for final weight may be based on early weight records. Genetic correlations between age of sexual maturation and live weights were low, favourable but had high standard errors. These results indicate that selection for high weight will potentially result in lower age of sexual maturation only with accurate determination of breeding values.

• Journal of Aquaculture
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• v.9 no.3
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• pp.279-285
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• 1996

The effects of various concentrations of $17{\beta}-methyltestosterone$ (MT) or $17{\beta}-estradiol\;(E_2)$ on sex reversal, survival and growth rates of olive flounder, Paralichthys olivaceus were investigated. MT and $E_2$ were treated to juvenile flounder for 60 days from 30 (total length : 14.5 mm) to 90 (TL : $10.41\~11.17$ mm) days after hatching. Fish were treated with 0, 1, 10 and 100 ppb of MT or $E_2$ in the rearing water for 2 hours per day. At the time of 200 days after hatching, fish were sampled to examine sex ratio. One hundred pub of MT produced $100\%$ male, however 1 and 10 ppm MT produced 72.5 and $87.2\%$ males. One, 10 and 100 ppb of $E_2$ produced 75.5, 91.9 and $97.2\%$ females, respectively. Survival and growth rates of each experimental group at the end treatment were not significantly different from those of the control (P>0.05).

• Fisheries and Aquatic Sciences
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• v.20 no.11
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• pp.29.1-29.7
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• 2017

The objective of this study was to determine a simple and reliable ploidy identification protocol for the rainbow trout (RT), Oncorhynchus mykiss, in the field condition. To evaluate the ploidy level and compare different detection protocols, triploid RT and gynogenesis were induced by UV irradiation and/or heat shock. The hatching rate at day 30 was 85.2% and the survival rate at day 90 was 69.4% (fingerling). The sex ratio of female RT was 93.75% in the gynogenesis group, illustrating that the UV irradiation inactivated the sperm DNA. The hatching rate and survival rate were 82.0 and 74.7%, respectively, in the triploid-induced group. The triploid induction rate by heat shock procedure was 73.9%. Cytogenetic protocols for ploidy identification such as chromosome counting, erythrocyte nuclear size comparison, and analysis of nucleolar organizing regions (NORs) by silver staining were compared. Silver nitrate staining showed the greatest success rate (22/23 and 32/32 for the triploid-induced group and gynogenesis group, respectively), followed by erythrocyte nuclear size comparison (16/23 and 19/32 for the triploid-induced group and gynogenesis group, respectively) and, lastly, chromosome preparation (2/23 and 6/32 for the triploid-induced group and gynogenesis group, respectively) with the lowest success rate. Based on our findings, silver staining for RT ploidy identification is speculated to be highly applicable in a wide range of research conditions, due to its cost-effectiveness and simplicity compared to other numerous ploidy detection protocols.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.3
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• pp.118-124
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• 2012

Objective: To review the outcomes of preimplantation genetic diagnosis (PGD) using zona drilling with acid Tyrode's solution (chemical zona pellucida drilling, chemical ZD) and those of partial zona dissection (PZD). Methods: Clinical outcomes of seventy-one couples undergoing 85 PGD cycles from January 2005 to December 2010 were included. Blastocyst formation and the hatching rate, clinical pregnancy rate, ongoing pregnancy rate, implantation rate, and fetal gender ratio of the PZD and chemical ZD groups were compared. Results: Application of PZD resulted in a significantly higher rate of clinical pregnancy (40.7% vs. 15.4%, p=0.022), ongoing pregnancy (35.6% vs. 11.5%, p=0.023), and implantation (18.1% vs. 5.7%, p=0.007) compared with chemical ZD. Among non-transferred embryos, the rate of blastocyst formation on day 5 (49.1% vs. 39.5%, p=0.016) and hatching on day 6 (47.2% vs. 26.5%, p<0.001) were also significantly higher in the PZD group. Conclusion: The mechanical zona dissection (ZD) method showed better outcomes than chemical ZD in terms of the blastocyst development and pregnancy rate. In this study, the fact that chemical ZD was conducted in different period from mechanical method should be considered in interpreting the result.

• Development and Reproduction
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• v.18 no.1
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• pp.33-41
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• 2014

We investigated the process of yolk absorption in Korean rose bitterling, Rhodeus uyekii, and determined the changes in its morphometric characteristics. The R. uyekii from 1 days post hatching (DPH) to 21 DPH, the eye diameter (ED) was 5.4 at 5 DPH. Thereafter, the ED/total length (TL) ratio increased to 10.7 at 21 DPH (p<0.05). The yolk length (YL) decreased from 95.4 to 1.1 by 21 DPH, and this rate of decrease was greater than that for any other dimension (p<0.05). 12 morphometric dimensions/TL for the R. uyekii were measured at each sampling day from 21 DPH to 170 DPH. At just hatching, the average TL and BW were $6.1{\pm}0.09mm$ and $4.9{\pm}0.07mg$, respectively. At 53 DPH, the average TL was $12.9{\pm}0.28mm$ and the average BW was $14.7{\pm}0.72mg$; the total length growth equation was $TL=5.507e^{0.038t}$ ($R^2=0.916$). Further, the body weight growth equation was $BW=3.3647e^{0.0296t}$ ($R^2=0.9354$). The dimensions with regard to body depth showed the greatest growth rates in the external characteristics of the fish (p<0.05). The patterns of the morphometric characteristics measured in this study can be classified in three ways. The patterns were shown to be increased (y=0.0992x+12.07, $R^2=0.8333$), decreased (y=-0.0569x+42.029, $R^2=0.8395$) or maintained (y=0.005x+18.263, $R^2=0.3678$) from 21 DPH to 170. These results will provide useful indices for the successful rearing of the R. uyekii.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.3
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• pp.119-125
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• 2017

Objective: In vitro culture of preimplantation embryos is improved by grouping embryos together in a drop of media. Individually cultured embryos are deprived of paracrine factors; with this in mind, we investigated whether the addition of a single embryo-secreted factor, interleukin-6 (IL-6), could improve the development of individually cultured embryos. Methods: Mouse embryos were cultured individually in $2{\mu}L$ of G1/G2 media in 5% oxygen and supplemented with a range of doses of recombinant mouse or human IL-6. Results: Mouse IL-6 increased hatching at doses of 0.01 and 10 ng/mL compared to the control (93% and 93% vs. 78%, p< 0.05) and increased the total number of cells at a dose of 0.1 ng/mL compared to the control ($101.95{\pm}3.36$ vs. $91.31{\pm}3.33$, p< 0.05). In contrast, the highest dose of 100 ng/mL reduced the total number of cells ($79.86{\pm}3.29$, p< 0.05). Supplementation with human IL-6 had a different effect, with no change in hatching or total cell numbers, but an increase in the percentage of inner cell mass per embryo at doses of 0.1, 1, and 100 ng/mL compared to the control ($22.9%{\pm}1.1%$, $23.3%{\pm}1.1%$, and $23.1%{\pm}1.1%$ vs. $19.5%{\pm}1.0%$, p< 0.05). Conclusion: These data show that IL-6 improved mouse embryo development when cultured individually in complex media; however, an excess of IL-6 may be detrimental. Additionally, these data indicate that there is some cross-species benefit of human IL-6 for mouse embryos, but possibly through a different mechanism than for mouse IL-6.