• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.1
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• pp.45-52
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• 2020

This study analyzed the components contained in the pine needles of first and second-year-olds to analyze the factors that the in vivo content of inorganic elements affects the sex determination of pine trees. In response, the plan for pine tree plant and maintenance was intended to be presented in consideration of the reproductive environment and physiological characteristics. The results are as follows. First, last year, when there were many encyclopedias, the analyzed N(%) content was found to be high. The nitrogen content of the previous year's soil was found to affect the production of the spheres the following year. This is believed to be possible to reduce the rate of Pine pollen produced in the new plant in the following year through a dispute over quality consumption in the spring of the previous year. Second, the weapons elements involved in the Pine cones and the generation of the Pine pollen in the new plant appeared to be P(%), K(%), Ca(%), and Fe(%). However, the nutrients from the previous year's leaves of Ca(%) and Fe(%) were found to have a low influence on the sex determination of first-year pine trees. Because Ca(%) and Fe(%) are not able to move nutrients accumulated in aging organs due to the nature of the components, feeding nutrients in the fall when the growth of the previous year's branches is reduced is expected to affect oral generation. Third, pine trees are extremely positive and Pine pollen is related to the time of the northeast wind. Therefore, it is believed that it would be good to be located in the northern direction, where the sunlight is good, in an outdoor space. In addition, it is important to use vaginal consumer products in spring and carry out a quarrel involving Mg and Fe during fall to reduce the effect of the Pine pollen, which is an outdoor plant. This is an important part of maintaining and managing pine trees in outdoor spaces as well as the sex determination of pine trees. This study suggested that plant planning, which derives the correlation between pine inorganic element content on sexual determination and takes into account the physiological characteristics of pine trees, is an important issue in the creation of outdoor space. Follow-up research on other factors affecting pine tree sex determination is expected.

• Journal of Aquaculture
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• v.6 no.4
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• pp.235-253
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• 1993

The freshwater crab, Eriocheir japonicus inhabits from sub-tropical to temperate zone in Asia. This species belongs to a large size group among freshwater crabs. Common size of this crab is 5-6cm in carapace length and occasionally 7cm in carapace length. This species of crab used to inhabit in estuaries, rivers and inland waters in Korea. However, natural population recently has been rapidly decreased because of pollution and lost their habitats by suburban development. Therefore, development of proper methods of seedling production to increase natural stock became necessity. As parts of achieving this goal, duration from mating to spawning, egg incubation period, and egg development of this species were studied. The influence of temperatures and salinities on the egg incubation and hatching was also investigated. It took 2-8 hours from mating to egg spawning and the spawning lasted 3-9 hours from the first spawning. Egg numbers per female (6cm in carapace length) were 380,000­410,000. Optimum temperature for egg incubation was $17\~23^{\circ}C$ and optimum salinity, $14.0\~31.5\%o$. Incubation period of the eggs at $14^{\circ}C,\;17^{\circ}C,\;20^{\circ}C,\;26^{\circ}C,\;and\;28^{\circ}C$ was 42, 28, 21, 15, and 14 days. respectively. Relation between temperature (X) and incubation days (Y) was LogY = Log 2764.267 - 1.608 LogX. A female can spawn 4-6 times per year by manipulation of environmental conditions. Under the conditions of $18^{\circ}C\;and\;24.5\%o$, it took 6 days up to embryo formation, 18 days up to compound eye formation, 22 days up to abdominal movement, and 25 days up to hatch out as zoea larvae.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.135-140
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• 2000

Development and reproduction of the cotton caterpillar, Palpita indica, were investigatedunder different temperatures (15 .O, 17.5, 20.0, 22.5, 25 .O, 27.5, 30.0, 32.5, and 35 .O$^{\circ}$C). Duration fromegg to pre-adult of the cotton caterpillar were ranged from 68.6 days at 175$^{\circ}$C to 19.7 days at 35.0% (3.5times shorter growth period compared with that at 17S$^{\circ}$C). At 15.0$^{\circ}$C, cotton caterpillar eggs developedto the last larval instar but were not able to go through the pupal stage. The lower developmentalthreshold temperatures and degree-days of egg, larva, pupa, and complete development were 13.4, 10.6,11.6, and 11.5"C and 55.3,251.5, 138.3, and 479.8 degree days, respectively. The hatching, pupation andemergence rates were higher at 25.0eC and 27.5"C compared with other temperatures. The survival ratefrom the hatched larva to adult was the highest at 27.5"C. The preoviposition and the adult longevity were11.5 and 30.6 days at 17.5"C and 1.5 and 9.2 days at 35.0$^{\circ}$C, respectively. The mean fecundity perfemales was greater at 25.0$^{\circ}$C and 27.5"C compared with other temperatures. Mean generation time indays (T) was shorter on higher temperature. Net reproductive rate per generation (R,) was the lowest atthe highest temperature as well as at the lowest, and it was 199.1 which was the highest at 27.5"C. Theintrinsic rate of natural increase (r,) was highest at 30.0$^{\circ}$C as 0.148. As a result, optimum ranges oftemperature for P. indica growth were between 25.0-32.5"C .emperature for P. indica growth were between 25.0-32.5"C .t;C .

• Korea journal of population studies
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• v.21 no.2
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• pp.182-227
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• 1998

Korean government decided to adopt an explicit population control policy in 1961 and from the following year the establishment and operation of the national family planning programme was included in each of the Five-Year Economic Development Plans that began in 1962. This policy was pursued in the understanding that without proper population control measures korea could not be able to achieve economic development. Korean national family planning programme is characterized by contraceptive target system through public health network with distribution of free contraceptives by family planning field workers and clinical contraceptive services such as IUD, vasectomy and tubaligation at designated clinics by the government. In addition, IE&C activities by the Planned Parenthood Federation of Korea and programme evaluation and research by the Korea Institute for Health and Social Affairs contributed to the development of the government programme. Between 1960 and mid 1980s the nation's total fertility rate was reduced from 6.0 to population replacement level of 2.1 and thereafter it has been maintained at 1.6 to 1.7 of below replacement level. With a short period of less than three decades fertility transition was completed in Korea. It is estimated that if the current level of below replacement fertility continues, the population in Korea stabilize at around 52.78 million people by the year 2028, and it will begin to decrease thereafter. Under this circumstances, the government adopted new directions and strategies of the population policy in June 1996, focused primarily on population quality and social welfare than on demographic arenas. In spite of over 80 percent of high contraceptive prevalence among married women, high incidence of induced abortions is maintained. Moreover, the prevalence of sex selective induced abortions using procedures to determine the sex of the fetus has resulted in an imbalance in the sex ratio at birth. In order to overcome those problems associated with reproductive health new policy for population quality control and health promotion programme should be highly strengthened in the future.

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.62-68
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• 2010

This study was conducted to find out how the germination, phenology and leaf morphology of Phytolacca insularis(endemic species of Korea) and P. americana(alien species) react to the global warming situation. Seed and seedlings of two species were sampled and placed under two separate conditions for the experiment. One of the seed and seedlings was treated in the glass house with control(ambient $CO_2$+ambient temperature, (AC-AT), and the other with control(elevated $CO_2$+ elevated temperature, EC-ET), over the period of one year, 2008-2009. The germination rate of two species was fast, and the time of their germination started early, when they were treated at EC-ET than at AC-AT. Furthermore, the germination rate of Phytolacca insularis(endemic species of Korea) was found to be comparatively lower than that of P. americana(alien species). The former showed only vegetative growth whereas the latter showed both vegetative growth and reproductive growth in one year period. The more $CO_2$ degree and temperature increased, phenological responses of two species, including leaf growth, the formation of flower stems, flowering, and fruit maturing, became much faster, and the time of their leaf-yellowing was delayed. The lamina length of P. insularis was not significantly affected by elevated $CO_2$ and temperature. The lamina length of P. americana, on the other hand, became longer at EC-ET than at AC-AT, but the leaf width of both species increased at EC-ET. As for the number of leaves, both species showed no difference. Finally, the ratio of the leaf area of P. insularis was high at AC-AT, but P. americana was high at EC-ET. These results indicate that P. americana, aliens species, reacts more sensitively to global warming than P. insularis, endemic species, does.

• Korean Journal of Agricultural Science
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• v.22 no.2
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• pp.156-162
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• 1995

This study was carried out to select the useful mutants among 20 lines treated with mutagen, gamma ray. These materials were treated with 15, 20, 25 and 30Krads, respectively and sowed at experimental field of College of Agriculture on 27th May, 1995. Items surveyed were germination rate and loss of chlorophyll at seedling stages, abnormal reproductive organs, discordance of flowering times and stem and ear height at ripening stages. The germination rate of lines treated with 15 Krad was different. The germination rate of the IK1, IK2 and Sinki lines were high, while the IK3, A632 and FR140 lines were very low. At same dose level, the germination rate of both IK1/H26 and Puyo synthetic variety were different; the germination rate of the IK1/H26 was high as above 70% at all treatments, while that of the Puyo synthetic variety was very poor at above 20 Krad. Generally stem adn ear height of the IK1/H26 were gradually decreased as the dose of mutagen increased, but there was no difference in stem and ear height of the IK1/H26 when this line was treated with 20Krad. The stem and ear height of lines treated with 15 Krad were shown to be decreased than those of check with non-treatment. The number of tiller of tillering lines were not greatly affected by ${\gamma}$-ray treatment.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.263-270
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• 2013

The vent sexing and the auto-sexing by using sex-linked traits are general sexing methods of day-old chicks. Currently, the feather sexing which is based on the differences in the feather characteristics at hatching is the representative sexing method of chicken, because the late-feathering is sex-linked trait. The feather sexing can be used if the breed has dominant feathering gene (K) in maternal and recessive gene ($k^+$) in paternal. Therefore it is necessary to identify the association of feathering genes and quantitative traits in chickens. In this study, we investigated the influence of the rate of feathering on productive traits in Korean Native Chicken. In results, there was no significant difference between early-feathering chickens and late-feathering chickens in reproductive performance such as fertility and hatchability. Livability, body weights, egg production, egg weight and egg quality also did not significantly differ between early- and late-feathering chickens. Age at first egg was the only trait of those tested in which significant difference was observed. The early-feathering chickens laid eggs 3 days earlier than late-feathering chicken. As a result, there is no influence of feathering phenotypes on productive performance in Korean Native Chickens. Consequentially, establishing the feather sexing strain is available using the Korean Native Chicken breed without considering of the effect of feathering genes on productive traits.

• Journal of Plant Biology
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• v.38 no.1
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• pp.95-105
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• 1995

Complete microsporogenesis of Hibiscus syriacus L. were carried out employing LM, TEM, and SEM to investigate the pollen ontogeny that undergoes considerable structural differentiation. The process first began with several cell diYisions in the anther primordium that produces 3 different tissues of epidennal, archesporial, and connective tissues. Only archesporial tissue involved further differentiation into the tapetum and formation of reproductive cells, pollen mother cells (PMC). The tapetum and PMC were closely associated with each other structurally and metabolically by exhibiting numerous plasmodesmata, mitochondria, and many small vacuoles in their dense cytoplasm. A callosic wall began to surround the PMC while meiosis took place in the PMC to produce 4 microspores. When thick callose encircled each microspore as a frame, the sporodenn development initiated from the plasma membrane of a pollen grain in a tetrad. The first fonned sporoderm layer was bacules and tectum of sexine that originated from the plasma membrane. After the dissolution of a callose, further development Qf sporoderm continued in the order of nexine 1, nexine 2, and intine layer. The nexine layer was thicker (ca. $2-3.5\;\mu\textrm{m}$) than the intine layer whose thickness was about $0.9-1.5\;\mu\textrm{m}$. Upon completion of the sporoderm development, that is after intine formation, spines and apertures of pollen surface ornamentation initiated from the tectum. Spines were dimorphic, about $4-9\;\mu\textrm{m}\;an;15-20\;\mu\textrm{m}$ in length, and no basal cushion was detected. The mature pollen grains ranged $100-200\;\mu\textrm{m}$ in diameter, but their average was about $170\;\mu\textrm{m}$. About 120 spines were observed over the spheroidal pollen surface. Apertures were simple punctures of $2-3\;\mu\textrm{m}$ in diameter and about 50 apertures were arranged somewhat helically over the surface. Comparing such features of form and size of the pollen, sporodenn sculpture and structure, and aperture and spine conditions with known evolutionary trends in the genus Hibiscus, Hibiscus syriacus seemed to possess many advanced features in the sporodenn differentiation.iation.

• Journal of Genetic Medicine
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• v.8 no.1
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• pp.44-52
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• 2011

Purpose: Cytogenetic analysis of spontaneous abortions (SABs) provides valuable information to establish the causes of fetal loss, information that is essential to provide accurate reproductive and genetic counseling couples. Such analysis also provides information on the frequencies and types of chromosomal abnormalities and associated risks of recurrence. However, there have only been a few reports of chromosomal abnormalities in small samples of SABs in the Korean population. Here, we report the incidence and spectrum of chromosomal abnormalities for cases of 470 SAB in Korea. Material and Methods: Between 2005 and 2010, a total of 470 products of conception (POC) resulting from SABs were submitted to our laboratory for cytogenetic analysis from various medical sites in Korea. The incidences and types of specific chromosomal abnormalities were determined. The abnormalities were distinguished by gestational age at the time of SAB and by maternal age. Results: The frequency of chromosomal abnormalities in POCs was 54.3% (255/470), including 228 (89.3%) numerical and 27 (10.7%: 3 balanced and 24 unbalanced) structural abnormalities. Among the numerical abnormalities, trisomy was predominant (67.0%), followed by monosomy X (12.5%), polyploidy (8.2%), triple X (0.8%), and autosomal monosomy (0.8%). The overall sex ratio (male: female) among the 470 POCs with normal and abnormal karyotypes were 0.58 and 0.65, respectively. Trisomies were identified for each autosome, with the exceptions of 1, 3, and 19. Among the 171 autosomal trisomies, trisomy 16 was the most common (19.9%), followed by trisomy 22 (13.5%), trisomy 21 (12.3 %), trisomy 15 (9.9%), and trisomies 18 and 13 (5.3%). The frequency of chromosomal abnormalities decreased with gestational age and increased with maternal age, but only because of increases in trisomies and complex abnormalities. Conclusions: We have presented a large collection of cytogenetic data for SABs collected during the past 6 years and provided a database for prenatal genetic counseling of parents who have experienced SABs in Korea.

• Korean Journal of Psychosomatic Medicine
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• v.16 no.2
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• pp.112-119
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• 2008

Objectives : Premenstrual syndrome(PMS) is known to occur in more than 80% of reproductive women. Since PMS is closely related to changes in sex hormones, biological factors are suspected to be associated with the syndrome, but there have been no consistent reports regarding biological causes. In that sense, it is postulated that the occurrence of PMS is much dependent on the biological aspects, but that the severity or characteristics of the syndrome is more dependent on the psychological factors. Studies focusing on psychological factors are based on the theory that symptoms of PMS and previous psychologically traumatic events are closely related. If the theory is valid, it can be further postulated that symptom severity of PMS is associated with dissociative symptoms, since traumatic events are known to be related to dissociative symptoms. In this study, we tried to find out the association of PMS symptom severity with previous abuse history and dissociative symptoms. Methods : Subjects for the study were 377 nurses working in Seoul, Kyung-gi, and Kyung-book. 183 subjects who submitted valid data entered the study. The presence and the symptom severity of PMS were rated using Daily Records of Severity of Problems(DRSP) and Shortened Premenstrual Assessment Form(SPAF). Dissociative symptoms were evaluated with Dissociation Experience Scale Korean version(DES-K). Previous physical/verbal abuse, sexual abuse, and parental spouse abuse experience were rated with correspondent abuse scales. Results : Subjects were divided into 3 groups as No PMS group, mild to moderate PMS group, and severe PMS group according to SPAF total score. There was a statistically significant difference in DES-K total score among 3 groups($x^2=14.966$, df=2, p=0.001). Physical/verbal abuse scale($x^2=14.397$, df=2, p=0.001), sexual abuse scale($x^2=8.376$, df=2, p=0.015), and parental spouse abuse scale($x^2=9.322$, df=2, p=0.009) also revealed a significant difference among 3 groups. Symptom severity of PMS using SPAF total score showed a positive correlation both with degree of dissociative experience and previous abuse experience. There was a statistically significant difference in both dissociative experience and previous abuse experience among 3 groups. Conclusion : These results show that there can be a possible association among PMS symptoms, dissociative symptoms, and previous psychologically traumatic experience.