• Horticultural Science & Technology
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• v.30 no.5
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• pp.573-578
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• 2012

A total of eleven Chinese cabbage accessions were used for microspore culture and were grown to take basal data. Based on the collected data, breeding materials were chosen to develop new improved Chinese cabbage cultivars. The range of microspore-derived embryoid taken from flower buds was 1.6 to 35.4 embryoids. The embryoids from IT26110 and IT26153 among the Chinese cabbages were more than 34 per flower bud. The viability rate after cold treatment was low from 0.2 to 11.7%. The range of fertility rate was 7.7 to 58.8% in general but the IT26118, IT26122, IT26128, IT26130, and IT26164 were more than 50%. The result of their seed production ability by selfing was 11.9 seeds per siliqua in IT26128 while the others were less than 10 seeds. In the microspore culture using parents of different hereditary, the number of embryoids, the number of plants, the rate of fertility and their pure seed production ability appeared to be very different in doubled haploid lines obtained from fertile plants of Chinese cabbage.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.77-87
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• 2018

The study was a mixed design study that analyzed the effects of developing and applying a program to improve pregnancy recognition for severe low fertility. The study period was from April 1, 2018, to October 26, 2018, and the participants included 16 women of 19~21 age who lived in M City and M Gun. The process of program development is based on Dorothy Johnson 's theory of behavior system to induce change of perception, and reference literature review and national policy report. The program developed through the literature was finally developed by examining the experts panel discussion after deriving causes and alternatives for low fertility from 25 fertility women. The contents of program consist of three areas. Quantitative research results were analyzed using Shapiro Wilk and Wilcoxon sign rank using SPSS 18.0, and qualitative research results were analyzed using focus group. As a result of study, the perception of pregnancy increased significantly (P<0.01) with statistical significance as pre-experimental (M=3.21, SD=.342), post-experimental (M=4.46, SD=.398) and the result of content analysis appeared three themes as , , . In conclusion, the program was effective in improving the recognition of pregnancy for young women.

• The Journal of Economics, Marketing and Management
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• v.5 no.2
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• pp.33-39
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• 2017

As the aging population geworsened by the a of the low fertility rate in the wake of the birth of the low birth rate, the rapid increase in the retirement age of the baby boomers in the wake of the birth of the Korean War is a significant indication of the separation of the aged and the role of the economically rich and the role of the role of the economically rich. Therefore, this study aims to address issues and countermeasures. The study aims to provide basic data for the future life of the baby boom generation by examining the problems and responses to the economic activity after the retirement activity of the baby boomers. The research suggests that the limit was limited to the retirement age of the baby boomer generation in order to boost the employment of the elderly. Due to the lack of exploration of the exploratory research, the lack of analysis of exploratory facts is the biggest limitation of the analysis. So, further analysis of this will lead to meaningful studies. Looking at the composition of this study, the introduction of the study included the necessity and purpose of the study. The focus on the point was on the concepts and characteristics of the baby boomer, and analyzed the characteristics of the economic activity and analyses and analyses of domestic and international cases. In conclusion, the issue was drawn up and the alternatives were sought.

• Clinical and Experimental Pediatrics
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• v.63 no.11
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• pp.415-421
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• 2020

Cryptorchidism or undescended testis is the single most common genitourinary disease in male neonates. In most cases, the testes will descend spontaneously by 3 months of age. If the testes do not descend by 6 months of age, the probability of spontaneous descent thereafter is low. About 1%-2% of boys older than 6 months have undescended testes after their early postnatal descent. In some cases, a testis vanishes in the abdomen or reascends after birth which was present in the scrotum at birth. An inguinal undescended testis is sometimes mistaken for an inguinal hernia. A surgical specialist referral is recommended if descent does not occur by 6 months, undescended testis is newly diagnosed after 6 months of age, or testicular torsion is suspected. International guidelines do not recommend ultrasonography or other diagnostic imaging because they cannot add diagnostic accuracy or change treatment. Routine hormonal therapy is not recommended for undescended testis due to a lack of evidence. Orchiopexy is recommended between 6 and 18 months at the latest to protect the fertility potential and decrease the risk of malignant changes. Patients with unilateral undescended testis have an infertility rate of up to 10%. This rate is even higher in patients with bilateral undescended testes, with intra-abdominal undescended testis, or who underwent delayed orchiopexy. Patients with undescended testis have a threefold increased risk of testicular cancer later in life compared to the general population. Self-examination after puberty is recommended to facilitate early cancer detection. A timely referral to a surgical specialist and timely surgical correction are the most important factors for decreasing infertility and testicular cancer rates.

• Korean Journal of Social Welfare
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• v.58 no.2
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• pp.223-249
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• 2006

The purpose of this paper is to classify OECD countries in regard to levels of supporting fathers' care work. Several meaningful conclusions were reached. First, examining the level of supporting fathers' care work and the strength of the traditional bread-winner model, OECD countries can be classified into 5 different clusters. The result is different from the mainstream typology of welfare states and suggests the new typology of welfare states. Second, the level of supporting fathers' care work and the strength of the traditional bread-winner model were found to be related to total fertility rates and women's labor market participation rates. Third, in regard to the level of supporting fathers' care work, Korea was the lowest among OECD countries. This result points to one of the important reasons to the low level of total fertility rat, and low rate of women's labor market participation in Korea.

• Journal of the Korean Regional Science Association
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• v.40 no.3
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• pp.43-61
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• 2024

The purpose of this study is to identify the difference of regional characteristics affecting 'marriage stage' and 'childbirth stage' and to compare how these factors differ between metropolitan and non-metropolitan areas using a heckman two-stage selection model. The main findings are as follows. First, regional characteristics affecting marriage stage and childbirth stage are different. Second, in the metropolitan area, regional characteristics such as population density, the proportion of female employee, and housing prices have a relatively greater impact on 'marriage', and in the non-metropolitan area, regional characteristics such as population density and unemployment rate have more impact on 'childbirth'. The empirical analysis suggests that marriage and childbirth stage need to be distinguished when establishing low fertility policies, and these approaches should be differentiated at regional level.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.211-217
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• 2013

A herd of polish lowland local sheep was divided into two equal groups: the first group was kept under an overhead shelter, and the second group was kept in a warm barn. The effect of maintenance on ewe's reproductive performance, survival as well as the growth rate of lambs, and their carcasses quality was investigated. The lack of differences in fertility and prolificacy of ewes as well as in the survival and growth rate between the groups confirmed a good adaptation of $\dot{Z}$ela$\acute{z}$nie$\acute{n}$ska sheep to low temperature. Harsh environmental conditions did not cause a significant decrease of the body weight growth; however, they brought in an (insignificant) reduction of subcutaneous fat thickness and meatiness of the loin part of a lamb's body. The fat content of carcasses obtained from lambs reared under the overhead shelter was significantly lower, with no differences of meat and bones contribution between the groups.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.1
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• pp.53-60
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• 1973

It is well known that upland soils in Korea are of low fertility, especially if newly reclaimed. Broadcasting of a sufficient rate of fused phosphate in addition to the normal dosage of fertilizer on such soils, may produce a crop yield comparable to that on ordinary upland soils, and the broadcasting of fertilities may build up soil fertility rather quickly. Building up fertility in this way will give a good crop growth on such newly reclaimed soils even under conditions where supplies of compost are limited. Since the precipitation in Korea is mainly concentrated in the months June through September, a complete cover of the land during this period is of major importance, requiring a well considered rotation and skilful management. If this is not possible, the application of a much of about 200 kg, straw per 1/10th ha. is recommended instead. Furthermore, contour cultivation on land with slopes less than five degrees, together with contour furrows, straw mulching, strip cultivation, interplanting, and proper selection of crops which provide a good cover of the land, is recommended on slopes varying between five and fifteen degrees and in addition, bench-terraces on slopes in excess of $15^{\circ}$.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.605-611
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• 2015

A synthetic strain of ducks (Anas platyrhynchos) was developed by introducing genes for long duration of fertility to be used as mother of mule ducklings and a seven-generation selection experiment was conducted to increase the number of fertile eggs after a single artificial insemination (AI) with pooled Muscovy semen. Reciprocal crossbreeding between Brown Tsaiya LRI-2 (with long duration of fertility) and Pekin L-201 (with white plumage mule ducklings) ducks produced the G0. Then G1 were intercrossed to produce G2 and so on for the following generations. Each female duck was inseminated 3 times, at 26, 29, and 32 weeks of age. The eggs were collected for 14 days from day 2 after AI. Individual data regarding the number of incubated eggs (Ie), the number of fertile eggs at candling at day 7 of incubation (F), the total number of dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) with plumage colour were recorded. The selection criterion was the breeding values of the best linear unbiased prediction animal model for F. The results show high percentage of exhibited heterosis in G2 for traits to improve (19.1% for F and 12.9% for H); F with a value of 5.92 (vs 3.74 in the Pekin L-201) was improved in the G2. Heritabilities were found to be low for Ie ($h^2=0.07{\pm}0.03$) and M ($h^2=0.07{\pm}0.01$), moderately low for Dm ($h^2=0.13{\pm}0.02$), of medium values for H ($h^2=0.20{\pm}0.03$) and F ($h^2=0.23{\pm}0.03$). High and favourable genetic correlations existed between F and Dm ($r_g=0.93$), between F and H ($r_g=0.97$) and between Dm and H ($r_g=0.90$). The selection experiment showed a positive trend for phenotypic values of F (6.38 fertile eggs in G10 of synthetic strain vs 5.59 eggs in G4, and 3.74 eggs in Pekin L-201), with correlated response for increasing H (5.73 ducklings in G10 vs 4.86 in G4, and 3.09 ducklings in Pekin L-201) and maximum duration of the fertile period without increasing the embryo mortality rate. The average predicted genetic response for F was 40% of genetic standard deviation per generation of selection. The mule ducklings' feather colour also was improved. It was concluded that this study provided results for a better understanding of the genetics of the duration of fertility traits in the common female duck bred for mule and that the selection of a synthetic strain was effective method of improvement.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.1
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• pp.63-69
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• 1986

1. Chemical components of fresh tobacco leaves at topping stages were affected variously by fertilizer application level. The more fertilizers were applicated, the higher nitrogen content of leaves was shown regardless of the soil fertility, but phosphorus content was not affected either by phosphorus rate or soil fertility. Potassium content was higher in the leaves grown in fertile soil than infertile at the same application rate. 2. Maturation of tobacco leaves was delayed by applying high level of nitrogen fertilizer, especially in fertile soil. The excessive accumulation of nitrogen in tobacco leaves at later stage of growth resulted in poor quality index for the high content of nicotine and low content of reducing sugar in cured leaves. 3. Nicotine content of cured leaf was increased significantly as nitrogen content increased, regardless of soil fertility, but reducing sugar content was reduced. Nicotine and reducing sugar content of cured leaf were higher in fertile than in infertile soil. 4. Resulting from the facts that nicotine contents were negatively correlated and reducing sugar contents were positively correlated with grading value (Won/Kg), authors suggested that grading index (Won/Kg) of the Office of Monopoly be based on quality index from chemical components of cured leaves.