• 제목/요약/키워드: Natural reproduction

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A study of the Characteristics of Community Design for Modern Industrial Heritage's Reproduction (근대산업유산 재생을 위한 커뮤니티디자인 특성 연구)

  • Jeong, Min-Joo;Lee, Chan
    • Korean Institute of Interior Design Journal
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    • v.23 no.4
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    • pp.157-168
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    • 2014
  • In buildings on the street, indiscriminate redevelopment are being made by overlooking the relationship with surrounding landscape to create their own unique meaning, due to industrialization progressed rapidly with human needs of longing for something constantly. Selection and methods of two plans, conservation and utilization should be required, considering heritage values on industrial buildings which are being lost and aged in this redevelopment higher. The attempt for the use of modern industrial heritage becomes a hot topic, and several experimental challenges are being made. However, there are rather many cases of causing industrial buildings' depreciation and one-size-fits-all reproduction performance as it applies other examples as standards by recognizing the reproduction of modern industrial heritage as one trend, not focusing on the trend of the times or paradigm, what the times want. To minimize these problems, we focus on how to utilize industrial buildings beyond the importance of industrial buildings' reproduction, considering the quality of local residents' life as well as the expected effect obtainable due to security of local identity and reproduction of buildings, focusing on the concept of community design that offers and forms a way of community life as the design of shares based on unspecified individuals' common life. Community design's core can be called to have diversity rather than undifferentiated unity by pursuing whole unification, since local residents become those who plan design and all people participate in it. In addition, community design achieves integration with other fields as an enlarged design area without limiting in an environmental area, by making indigenously natural characteristics combined with cultural factors in one context so that people may understand the flow of the place. The importance of effects acquired from modern industrial heritage's reproduction has well-known, and the attempt for utilizing aged heritage as a new value and a function has constantly been made. Now, it's time to focus on how long it lasts through this method, rather than modern industrial heritage's reproduction itself. There can be a significance in this study in proposing methodological solutions on modern industrial heritage's reproduction, not to cause depreciation of industrial buildings by recognizing contemporary trends and uniform regeneration performance, multifaceted research is needed for creative, effective development on modern industrial heritage which will occur constantly.

Effect of Pregnancy Rate Following Timing of Artificial Insemination after Estrus of Hanwoo Female

  • Yang, Jung Seok;Heo, Young-Tae;Uhm, Sang Jun;Ko, Dae Hwan
    • Reproductive and Developmental Biology
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    • v.37 no.2
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    • pp.75-77
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    • 2013
  • This study was conducted to investigate optimal time of artificial insemination (AI) to Hanwoo female after natural estrus. AI was occurred 12 and 24 hours after natural estrus in both heifer and multiparous recipient then pregnancy and parturition rates were estimated. Results indicated that AI performed at 24 hours after natural estrus showed significant (p<0.05) higher pregnancy rate in both heifer and multiparous recipient groups with significantly (p<0.05) higher abortion rate. However, there are no significant differences of parturition rate, twin birth and sex ratio in both heifer and multiparous recipient groups. Therefore, our results may suggest that performance of AI at 24 hours after natural estrus promise higher pregnancy rate than AI at 12 hours after natural estrus in both heifer and multiparous recipient.

Suitability Assessment of Domestic Natural Waters as a Culture Medium for Daphnia magna (Daphnia magna의 배양배지로서 국내 자연수의 적절성 평가)

  • Yeom, Dong-Hyuk;Jeon, Chan-Sig
    • Korean Journal of Ecology and Environment
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    • v.45 no.3
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    • pp.271-277
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    • 2012
  • The present study was conducted to assess the suitability of domestic natural waters as a Daphnia magna culture medium. In order to assess survival rate and reproductive output, young female daphnids (parent animals), aged less than 24 hours at the start of the test and produced in the Elendt M4 medium, were exposed to Elendt M4 medium, de-chlorinated tap water, and natural mineral water for 21 days. D. magna cultured in Elendt M4 medium (reference medium) and natural mineral water met the criteria of OECD No. 211, Daphnia magna Reproduction Test Guidelines in terms of percent adult survival, first day of reproduction, and average young production. However, the mortalities of adult daphnids observed in de-chlorinated tap water were more than 20% in two reproduction tests for 21 days. Mortality was observed on exposure days 13, 15, and 18 in de-chlorinated water. The use of D. magna is recommended in water of hardness >80 mg $CaCO_3\;L^{-1}$. However, the hardness of de-chlorinated tap water used in the present study was 50~53 mg $CaCO_3\;L^{-1}$. Therefore, it is judged that the delayed mortalities observed in de-chlorinated tap water were caused by a rapid decreased in hardness when the medium was changed from Elendt M4 to de-chlorinated tap water. When D. magna is cultured using domestic natural waters (underground water, surface water, and de-chlorinated water), the quality-control (QC) data should be maintained through a standardization for health assessment method, toxicity test method using reference chemical, test intervals of reference toxicant toxicity test, and data treatment and interpretation. In the long term, national research programs are needed for the development of test species which are representative of domestic aquatic environmental conditions among indigenous daphnids.

The Effect of Day Length and Lunar Phases on the Spawning Activity in the Nile Tilapia Oreochromis niloticus

  • Kwon, Joon-Yeong;Kim, Jung-Hyun;Kim, Bo-Kyong
    • Development and Reproduction
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    • v.14 no.1
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    • pp.21-25
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    • 2010
  • Nile tilapia (Oreochromis niloticus) are mouth-brooders so that the females holding eggs in their mouth sacrifice their somatic growth for reproduction. For this reason, artificial control of reproduction for the culture of this species has been of interest. Manipulation of photoperiod is an emerging technique for such purpose, but little information is available to establish appropriate photoperiod regime. To obtain necessary basic information, sexually mature females were individually accommodated to glass aquarium, and the spawning activity of these females were monitored for two years under natural photoperiod regime. Female tilapia spawned most frequently on March, April and May when the day length gradually increased from 11 hours to 14 hours and least frequently on September, October, November and December when the day length gradually decreased from 13 hours to less than 10 hours in the first year. The decrease of spawning frequency as day length decreased was also observed in the second year, although the increase of spawning frequency as day length increased was less clear. Spawning of female tilapia was less active when the night was dark due to the disappearance of moonlight (Dark Phase), compared to the Phase of Getting Lighter, Light Phase and Phase of Getting Darker. Results from this study suggest that long day length, particularly increasing phase, is favoured for active spawning of Nile tilapia, and that this species, as a tropical fish species, may utilize changing lunar phases as a secondary environmental cue for reproduction.

Effect of Diets on Development and Reproduction of Rice Armyworm, Pseudaletia separata (Lepidoptera: Noctuidae) (멸강나방의 발육과 생식에 미치는 먹이의 영향)

  • 김길하;고해랑;김정화
    • Korean journal of applied entomology
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    • v.41 no.2
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    • pp.85-89
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    • 2002
  • Development and reproduction of the rice armyworm, Pseudaletia separara, were investigated on different diets (corn leaf, rice leaf, Chinese cabbage leaf, cabbage leaf, sweetpotato leaf, soybean leaf and silkworm artificial diet). Egg and pupal periods were not different among the diets. But larval periods showed significant difference among diets. Developmental period from egg to adult was shortest as 32.5 d on corn leaf and longest as 46.6 d on soybean leaf. At 16 days after hatching, larval weights on rice and silkworm artificial diet were heavier than those on other diets. The larvae reared on cabbage leaf and sweetpotato leaf failed to pupate. Survival rates from larva to adult were highest (70.6%) on com leaf lowest (39.8%) on soybean leaf. The longevity of female adults was not affected by the larval diets. Female adults showed higher fecundity when the larvae were fed with corn leaf, rice leaf and silkworm artificial diet than other diets. Net reproduction rate (R$_{0}$) was highest as 1218.5 on silkworm artificial diet. The intrinsic rate of natural increase (R$_{0}$) ranged from 0.115 to 0.175, and was maximum on com leaf.

A Study for the Expression of Melatonin Receptor Gene and Reproductive Indices in Golden Hamsters Exposed to Photoperiods (골든 햄스터에서 광주기에 따른 멜라토닌 수용체 유전자 발현과 생식 지수들에 관한 연구)

  • Choi, Donchan;Choi, Hyungjae;Lim, Sinae;Park, Changeun
    • Development and Reproduction
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    • v.6 no.1
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    • pp.45-54
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    • 2002
  • Reproductive activity of golden hamsters(Mesocricetus auratus) is regulated by the photoperiod. They are sexually active in summer and inactive in winter. Melatonin, a pineal hormone, has been known to mediate sexual activities in seasonal breeding animals. Melatonin receptor was recently identified in several animal species including hmm. But little has been known about it in relation to the reproductive activities of golden hamsters. By using reverse transcription polymerase chain reaction(RT-PCR) methods, a portion of the melatonin receptor gene(309 nucleotides) was identified in golden hamsters. The nucleotide sequence of the melatonin receptor and the amino acid sequence deduced were compared to those reported in other animals. Melatonin receptors were obviously detected in hypothalamus, pituitary containing pars tuberalis, blood, and spleen. Although the testicular weights and the levels of reproductive hormones were dramatically affected by photoperiods, the expression of melatonin receptor was not markedly changed by them. These results suggest that the action of melatonin in regulating reproduction might be mainly due to the affinity of melatonin receptor rather than the density fi melatonin receptor.

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Utilization of Porcine Clotted and Dried Blood for Estrogen Receptor Gene PCR-RFLP (에스트로겐 수용체 유전자의 다형 현상 추정을 위한 응고 및 건조된 돼지 혈액의 이용)

  • Seo, D.S.;Yang, S.H.;Park, H.B.;Park, S.S.;Hong, K.C.;Ko, Y.
    • Korean Journal of Animal Reproduction
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    • v.23 no.2
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    • pp.159-163
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    • 1999
  • Recent development of the molecular biology techniques has made it possible to characterize and analyze early diagnoses of genetic disorders and economic trait loci. In this study, porcine genomic DNA was extracted from both clotted and dried blood to analyze the porcine estrogen receptor (ER) gene by polymerase chain reaction (PCR). By the methods reported here, genomic DNA extracted from clotted or dried blood was efficient enough to detect ER gene by PCR. Moreover, the PCR-RFLP (restriction fragment length polymorphism) of ER gene was identified by PvuII restriction enzyme. Thus the results obtained from this study show that the clotted and dried blood was useful for identification of the certain genotype in a rapid manner with low cost. Importantly, this study implies that the whole blood can be economically utilized in studies of endocrinology, molecular biology, and genetics by obtaining both serum and DNA simultaneously in an efficient manner.

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Natural vs synchronized estrus: determinants of successful pregnancy in ewes using frozen-thawed Suffolk semen

  • Rahman, Md. Mahbubur;Naher, Nazmun;Isam, Md. Mofijul;Hasan, Moinul;Naznin, Farhana;Bhuiyan, Mohammad Musharraf Uddin;Bari, Farida Yeasmin;Juyena, Nasrin Sultana
    • Journal of Animal Reproduction and Biotechnology
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    • v.35 no.2
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    • pp.183-189
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    • 2020
  • The pregnancy rate in indigenous ewes inseminated with frozen-thawed Suffolk semen following natural and synchronized estrus was determined. The serum Progesterone and Estrogen concentration and vaginal electrical resistance (VER) of ewes at the time of Artificial Insemination (AI) were observed as successful pregnancy determinants. 21 healthy ewes were selected for this experiment during January-April, 2017. 10 ewes were inseminated in natural estrus. Whereas, 11 ewes were inseminated after estrus synchronization using intravaginal sponges containing 60 mg medroxyprogesterone acetate. Trans-cervical Al (TCAI) was performed in all ewes within 12-16 hours of observed heat. Prostaglandin E1 analogue impregnated vaginal sponge was used for cervical relaxation 6-8 hours before insemination. Pregnancy was diagnosed through trans-abdominal ultrasonography after 40 days of AI. The pregnancy rate of ewes in synchronized estrus was higher (54.5%) than in natural estrus (30%). Higher serum Progesterone level (0.90 ± 0.02 ng/mL) and significantly (p < 0.001) lower VER (257.78 ± 10.11 ohm) were observed at the time of AI in ewes becoming pregnant. Results suggest that higher Progesterone concentration and lower VER could be considered as pregnancy indicators. Oestrous synchronization could be implemented to increase the pregnancy rate in ewes.

Effects of Endocrine Disruptors on Endocrine Function and Reproductive Function in Wildlife and Humans (내분비교란물질이 야생동물 및 인간의 내분비기능과 생식기능에 미치는 영향)

  • 류병호
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.5
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    • pp.1180-1186
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    • 1999
  • A wide ranges of chemicals released into the environment have potential to interfere with physiological and development process by disrupting endocrine pathways. Endocrine system embraces a multitude of mechanisms of action, including effect on growth, behavior, reproduction and immune function. These environmental endocrine disruptors are present in environment and pose potential health consequences to human and wildlife. The best known form in endocrine distruptors involves substances which mimic or block the action of natural hormone in the body. Endocrine disruptor have been variously defined as exogenous agents that interfere with the synthesis, secretion, transport, metabolism, binding action or elimination of the natural hormones in the body which are responsible for the maintenance of homeostasis, reproduction developmental and/or behavior. Many compounds polluted into the environment by human activity are capable of disrupting the endocrine system of animals, including fish, wildlife, and humans. Among these chemicals are pesticides, industrial chemicals, and other anthropogenic products. It has been alleged that several adverse effects on human health are linked with exposure to chemicals which are claimed to be endocrine disrupters, that is, increased incidence of testicular, prostate and female breast cancer, time dependent reductions in sperm quality and quantity, increased incidence of cryptorchidism (undescended testicles) and hypospadias(malformation of the penis), altered physical and mental de velopment in children. This observation is currently the only example of chemically mediated endocrine disruption which has resulted in a clear effect at the population level.

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SHADE ANALYSIS OF ARTIFICIAL TEETH USING SHADE $SCAN^{TM}$ SYSTEM (ShadeScan$^{TM}$ System을 이용한 인공치의 색조분석)

  • Sung, Chai-Ryun;Cho, In-Ho;Lee, Jong-Hyuk
    • The Journal of Korean Academy of Prosthodontics
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    • v.42 no.4
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    • pp.443-457
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    • 2004
  • Purpose: The purpose of this study was to analyze and estimate whether each company may produce the color of artificial teeth as it stands, in the standard of vita classical shade guide using ShadeScan$^{TM}$ System. Material and methods: we chose the products of 6 companies -EFUCERA, IVOCLAR, ENDURA, TRUBYTE, DURADENT, and DURACROSS- estimated the shade value of each fixed point(cervical, body, and incisal area) of artificial tooth, and verified the equality among the samples from the same company. Results: First, the variation appeared significant at cervical and incisal area. It means that there were significant differences between cervical and incisal area although the most similar artificial teeth to the patients’natural teeth were provided. Second, the results in the body area showed that the variation between artificial and natural teeth was finite(p<0.05) in that area. Conclusion: it shows that the reproduction of colors of artificial teeth might be successful regarding the body is the most important part for a determination of the color of artificial teeth. However, more complements are necessary for the better reproduction of the color of artificial teeth between cervical and incisal area.